Last Updated on 2nd April 2025
The color grade of a lab-grown diamond is a hugely important factor when it comes to the overall appearance of the diamond. Just like a natural diamond a lab-created diamond can still have color tint imperfections that occur during the manufacturing process.
In this article we will give you a complete deep-dive into what causes different color grades in a lab-grown diamond and which is the best color grade to choose for a lab-grown diamond. We will also get into the nitty-gritty details of HPHT and CVD diamonds and how it relates to the diamond color grade.
What is Diamond Color?
Diamond color for lab-grown diamonds is graded on a scale from D-Z by IGI (International Gemological Institute). Please note that we recommend you buy a an IGI-certified diamond when it comes to lab-grown diamonds. For natural diamonds we prefer a GIA-certified diamond because they are a little stricter in their grading. However, IGI has certified much more lab-grown diamonds because their grading service is cheaper and thus they have become the quasi-authority for lab-created diamonds.
The higher the color grade of a lab-grown diamond the whiter and more brilliant it will appear. That however is not necessarily a good enough reason to choose the highest possible color grade.
How is Diamond Color Graded in Lab-Grown Diamonds?
When a lab-grown diamond is created, it goes through the same grading process as a natural diamond. That includes the evaluation of color. Color is one of the four key quality factors, alongside cut, clarity and carat weight. Grading is done by trained gemologists in specialized laboratories like IGI or GIA, under very controlled lighting conditions.
To determine the color, the lab-grown diamond is placed face down on a white background and compared to a set of master stones. These master stones are natural diamonds with known and certified color grades, and they range from completely colorless to noticeably tinted. The gemologist compares the lab-grown diamond side by side to this master set to see where it best fits. That’s how the final color grade is decided.
For lab-grown diamonds, IGI is the lab that currently grades most of them. They use a scale that goes from D to Z, just like for natural diamonds. D means completely colorless, and Z means a noticeable yellow or brown tint. Most lab-grown diamonds on the market today fall somewhere between D and J. Anything below J is usually considered to have visible color to the naked eye, especially in larger stones or when set in white metals.
It’s important to understand that color grading is not done with machines. It is still a human judgment call, even though the environment is controlled. That means two diamonds with the same color grade may look slightly different. And sometimes a diamond with a lower color grade might even appear brighter than one with a higher grade. This is why comparing diamonds visually is always a good idea if you are unsure.
As you’ll see in more detail later, the production method also plays a role in color. HPHT diamonds tend to have yellow or blue tones due to trace elements like nitrogen or metals used in the growth process. CVD diamonds can have a brown tint due to internal stress in the crystal. That is why most lab-grown diamonds are treated after growth using a heating process to improve their color. This is called HPHT annealing and it helps bring them into the colorless or near-colorless range.
So while color grading in lab-grown diamonds follows the same scale as natural diamonds, there are a few more layers to it. You are not only looking at the grade on paper but also at how the diamond was grown and whether it was treated to improve the color. All of this influences how the diamond actually looks once set on a ring and worn in real life.
How HPHT and CVD Growth Impact Diamond Color
One helpful detail is that IGI certificates let you know which process was used in the production of lab-grown diamonds. By the way, James Allen currently has the largest inventory of lab-grown IGI-certified diamonds in the world. Lab-grown diamonds can either be produced by the High Pressure High Temperature method (HPHT) or by the Chemical Vapor Deposition method (CVD). On the left we have a 1.5 carat lab-grown diamond produced by the HPHT growth process and on the right we can see a 4 carat lab-grown diamond produced by the CVD method. The IGI-certificate clearly states the method that was used. This is currently not the case for lab-grown diamonds certified by GIA.
HPHT Diamonds and Color
The HPHT method most closely mimics the way natural diamonds form in the Earth’s mantle. A diamond seed (an existing diamond or pure carbon) is placed in a chamber with extremely high pressure (5-6 GPa) and temperatures exceeding 2,700°F (1,500°C) to grow the diamond crystal.
As mentioned earlier, HPHT diamonds can develop a yellowish tint when nitrogen atoms get trapped in the crystal lattice during the growth process. Below you can pick up a slight yellowish tint in the E, H and I-graded HPHT lab-grown-diamonds. In general HPHT lab-grown diamonds produce a more uniform color than CVD diamonds because the growth process is more thermodynamically stable. Although for all practical purposes it won’t make much of a difference if you choose an HPHT or CVD lab-grown diamond. We are talking about very minute differences that you might be able to pick up on if you compare two diamonds next to each other under very strong magnification.
HPHT diamonds are grown using a metallic catalyst (like iron, cobalt, or nickel) that helps facilitate the crystal growth and dissolve the carbon. This can result in a metallic flux contamination which can result in a grayish or bluish tint. In the picture below you can see a very slightly bluish and grayish tint in the G color HPHT diamond. However, the tint should be only very slight blue in high-quality HPHT diamonds. In fact this very diamond will look perfectly fine when set on a ring. Premium HPHT diamonds from top manufacturers also go through a purification processes to remove excess metallic contamination, making visible inclusions of this type very rare.
Interestingly, the image below also highlights how diamond color grading is ultimately a human process. The F-color diamond appears noticeably icier than the E-color diamond next to it, despite being technically a lower grade.
The purification process consists of treating an already grown diamond again with extremely high temperatures. This removes most of the yellow tint that was caused by the nitrogen inside the lattice and it will also remove any grayish or bluish tint that was caused by the metallic flux contamination. This process is called HPHT annealing and most D-F grades colorless HPHT diamonds have been treated this way.
CVD Diamonds and Color
The CVD method on the other hand grows diamonds in a plasma chamber under low pressure using carbon-rich gas like methane or hydrogen. Plasma is the fourth state of matter and gas is converted into plasma when it keeps being heated to ever higher temperatures.
Unlike the HPHT method, CVD diamonds are grown in layers, which creates internal stress in the crystal structure. This internal stress can cause the diamond to appear brownish. This happens when the growth process happens too fast and the carbon atoms don’t have the time to arrange themselves properly. This leads to missing carbon atoms and vacancy defects, which absorb certain wavelengths of light and make the diamond appear to have a brownish tint.
As previously explained, the brownish color in CVD diamonds is not due to nitrogen but rather defects in the crystal caused by internal stress during the growth process. Below you can see that the lower color grade CVD diamonds indeed tend to appear more brownish as opposed to yellowish as is the case with HPHT lab-grown diamonds.
Since CVD diamonds don’t use a metallic catalyst, they don’t usually have the bluish or grayish tint, that is sometimes associated with HPHT diamonds. But it is common for lower color grade CVD diamonds to appear brownish due to the internal stress. CVD lab-grown diamonds use the the same HPHT annealing process to remove the brownish tint and improve clarity. Without this treatment all CVD diamonds would display a brownish hue. All CVD diamonds with a D-F color grade have been treated this way.
Which Method Produces Better Color?
In general it is thought that in terms of diamond color HPHT diamonds are slightly preferable because they produce a slightly more uniform color although this is very hard to pick up on in practice. For instance from the HPHT and CVD Diamond Color chart nobody can really pick up on the theoretical benefit of a more uniform color of HPHT diamonds compared to CVD diamonds. Both have their pros and cons but none of those really matter in practice.
| Lab-Grown Diamond Color Comparison – HPHT vs CVD | ||
| Factor | HPHT Diamonds | CVD Diamonds |
|---|---|---|
| Common Color Issues | Yellow (nitrogen), Grey/Blue (metallic contamination) | Brown/Grey (lattice strain) |
| Uniform Color? | More uniform | Less uniform, can have uneven patches |
| Nitrogen Presence? | More nitrogen (yellow tint) | Almost no nitrogen (no yellow tint) |
| Post-Growth Treatment Needed? | Sometimes (to improve color) | Almost always (to remove brown/gray from lattice strain) |
| Best for D-F Color? | HPHT-treated or high-quality HPHT growth | HPHT-treated CVD |
Thanks to HPHT annealing as an after-treatment both HPHT and CVD diamonds can reach the highest D-F color grades. However, one advantage that CVD diamonds have over HPHT diamonds is that they are slightly more affordable giving you a little bit more room to go for a larger carat size.
How to Choose the Right Color for Your Lab-Grown Diamond Ring
What is much more important than whether you buy an HPHT or a CVD lab-grown diamond is which color grade you choose. In general we don’t recommend to go for a colorless grade in the D-F color range, because the diamond will pick up some of the ring metal’s color anyways. Our general guidelines for round cut lab-grown are as follows:
| Lab-Grown Diamond Color Scale | |
| Color Range | Description & Recommendations |
|---|---|
| Colorless (D–F) | Completely transparent, with no noticeable color even under magnification. It’s not necessary to buy a colorless diamond but if you are going to do so anyways we only recommend to pair it with a platinum or white gold ring setting, which enhance their icy brilliance. This platinum ring setting from James Allen for instance would be a great fit. |
| Near Colorless (G–J) | Has a slight hint of color, but it is often not visible to the untrained eye. These diamonds offer an excellent balance of beauty and value. When set in platinum or white gold, they still appear nearly colorless. In yellow or rose gold settings, the warmer tones blend well with the diamond, making any color presence less noticeable. |
| Faint Color (K–M) | Displays a noticeable yellow or brown tint, especially in larger stones. More affordable and best suited for yellow gold settings, as the metal’s warm tone complements and masks the diamond’s color. Platinum or white gold settings may emphasize the yellowish hue and are not recommended. This yellow gold ring setting from Blue Nile could be a great fit for a faint color lab-grown diamond for instance. |
As we covered earlier, color grading is not machine-calculated. It’s done by gemologists who compare the diamond to a set of certified master stones. They determine where it fits in relation to this master set. But even with these controls in place, it’s not a perfect science.
For instance on the lab-grown HPHT diamond color scale above you might have noticed that the F-color diamond appears with less tint than the E-color diamond. Although the E-color diamond has a higher color grade and should have less tint than the F-color diamond.
Another great example would be this 1.20 Carat G-color lab-grown diamond from James Allen. If you look at it very closely you will see that it really still is icy white. Then compare it to this 1.19 carat F-color lab-grown diamond from Blue Nile. The F-color diamond is one color grade higher and if anything it should be brighter. But it very clearly displays much more body color, namely a slightly yellowish hue. This actually happens quite often in diamond grading. Therefore, ideally you want to take your time when buying a lab-created diamond to be able to thoroughly compare different lab-grown diamonds to each other.
That’s why it is essential to have a large inventory of lab-grown diamonds to choose from. James Allen currently has the largest lab-grown diamond inventory, which is ideal for comparing diamonds to each other. Whiteflash on the other hand offers a much smaller inventory but for diamond cut aficionados it offers a world-class diamond cut inventory of lab-grown diamonds and is certainly worth having a look at.
And of course you also have to consider which ring metal and diamond shape you will be using. 70% of people buy round-cut lab-grown diamonds. The round cut diamond reflects light the best and is the most brilliant. As other diamond shapes are less brilliant you also want to take that into consideration.
What Color Grade is Best for Your Setting?
Choosing the right diamond color doesn’t just depend on the diamond itself. It also depends on the ring metal and diamond shape. Some combinations enhance a diamond’s appearance, while others can make slight color tints more noticeable. Here’s a simple guide to help you pair the right color grade with your setting:
| Best Diamond Color Grades by Ring Metal and Shape | |||
| Diamond Shape | White Gold / Platinum | Rose Gold | Yellow Gold |
|---|---|---|---|
| Round Cut | D-F (Colorless) for the best brilliance, G-H (Near Colorless) for great value | G-I (Near Colorless to Faint) blends well with the warm tone of rose gold | I-J (Faint) blends seamlessly with yellow gold, K-M for a more antique look |
| Emerald, Princess, & Asscher Cuts | D-F (Colorless) as these cuts reveal more color due to their step-cut facets | G-I (Near Colorless) offers a great balance of color and value | H-J (Near Colorless to Faint) works well, with K-M giving a vintage feel |
| All Other Diamond Shapes | D-G (Colorless to Near Colorless) ensures a bright appearance | G-I (Near Colorless) blends nicely with rose gold’s warmth | I-J (Faint) pairs well, with K-M giving a richer, warmer look |
While diamond color plays an important role in the overall appearance of a diamond, it’s worth remembering that once your lab-grown diamond is set in a ring, it will reflect some of the ring metal’s color. In practice, that means it’s often difficult to spot the difference between a D-color and a J-color diamond, especially in a yellow gold setting.
Below, you can see a D-color diamond on the left and a J-color diamond on the right. On paper, that’s a big difference. And yes, the D-color still looks a bit more icy white — but mostly because it’s placed right next to the J. The difference is much more subtle than most people expect.
That being said, you would definitely be able to pick up the difference between a D- and J-color diamond on a white gold ring setting. To get the best bang for your buck we recommend to stay clear of the colorless range between D-F altogether. Even for white gold and platinum ring settings.
You will be even hard pressed to really notice a difference between a D- and G-color diamond mounted onto a platinum or white gold ring setting for instance. The near colorless G-J color range provides the best value for a lab-grown diamond that you want to use on an engagement ring.
To demonstrate that even further here below we two lab-created diamonds on a platinum ring setting. An F-color lab-created diamond above and an H-color diamond below. Mind you, the difference between an F- and H-color grade is only two color grades. And I do think that the F color diamond looks a tiny bit more brilliant but it’s really hard to make out even on platinum ring setting.
Conclusion: So unless you’re comparing diamonds side by side under strong lighting, chances are you won’t spot much of a difference, but your wallet definitely will. For most buyers, sticking to the near colorless G–J range offers the best balance of beauty and value.
Lab-Grown Diamond Color and Resale Value
Of course, buying a lab-grown diamond is a topic of its own. One thing you absolutely need to be aware of is that lab-grown diamonds currently have very little resale value. Unlike natural diamonds, which can usually be sold back to a jeweler or second-hand buyer even if it’s at a reduced price, there is no established resale market for lab-grown stones. Companies that specialize in buying second-hand diamonds from consumers generally do not accept lab-grown diamonds at all.
You might still be able to sell a lab-grown diamond privately on platforms like eBay, Facebook Marketplace or through local classifieds. But you would likely need to accept a significant discount, and even then it might take time to find a buyer who is actually interested. The main reason for that is the rapid price drop over the last few years. It has created a lot of uncertainty. No buyer wants to risk purchasing a diamond that could be worth much less in just a few months.
And this holds true no matter the color grade. Even if you buy a lab-grown diamond with a top-tier D or E color grade, the resale value won’t hold up the way it might for a natural diamond. The market simply isn’t rewarding those higher grades when it comes to resale. That’s because the supply of lab-grown diamonds is growing rapidly and prices continue to adjust downward, regardless of how “perfect” the diamond looks on paper.
This situation is closely tied to the fact that lab-grown diamond prices are still finding their bottom. While the steepest price drops are likely behind us, experts believe that prices will continue to decline slowly until the market reaches full maturity. But there is a bright side to this. Right now is probably the most affordable time in history to buy a large lab-grown diamond. What used to be completely out of reach, like a two or even four carat diamond, has suddenly become realistic for many buyers.
In short, if you are buying a lab-grown diamond, it makes the most sense to treat it as a personal purchase rather than a financial investment. You are paying for the beauty, the brilliance, and the emotional value, not for resale potential. And that is perfectly fine. As long as you go into it with that mindset, you are going to enjoy the experience much more.
Our key takeaway
Our top recommended place to buy a lab-created diamond is James Allen with the largest collection of lab-created diamonds. We also love Blue Nile with the second largest collection of lab-grown diamonds. Likewise we wholeheartedly recommend Whiteflash for diamond cut aficionados. Here you can even save 100 USD on a Whiteflash purchase.
If you were dead-set on buying a D-color diamond we would rather recommend you choose a G- or H-color diamond and invest the price difference in a better cut or larger carat size.
At the end of the day, don’t let the idea of finding the “perfect” color stress you out. Color is just one piece of the puzzle and once your diamond is set, worn, and catching the light, most subtle differences disappear. Focus on what actually enhances the overall beauty: a strong cut, a balanced carat size, and a color that fits both your setting and your budget. If you keep that in mind, you’ll end up with a lab-grown diamond that not only looks stunning but also gives you the best bang for your buck and that’s what really counts.
Common Questions About Lab-Grown Diamond Color
Why does my lab-grown diamond look warmer at home than in the store?
Because stores use super-white LED lighting that makes any diamond look icy. At home, under warmer light bulbs, the true color becomes more apparent. Try comparing it in natural daylight for the most honest read.
Are pink or blue lab-grown diamonds naturally that color?
Usually not. Most colored lab diamonds are treated with irradiation or high-temperature annealing to achieve those vivid hues. Still 100% real diamonds, but just given a scientific makeover.