How Are Colored Lab Grown Diamonds Made?

Yes. A Lab Grown Diamond is a real diamond: crystallized carbon with the same crystal structure as a mined diamond, a 10 on the Mohs scale, and the same way of bending light. Add color to it and none of that changes. A fancy color Lab Grown Diamond is that same real diamond, carrying real color.

The color is not painted on. It lives in the diamond's own chemistry and crystal structure, exactly the way color arises in a natural fancy color diamond. In fact, most colored diamonds you will ever see, mined or Lab Grown, owe their color either to a trace element caught in the crystal or to a later treatment. That is normal for the category, and it does not make a stone any less of a diamond. If you want the groundwork on the material itself, see our guide on what a Lab Grown Diamond is and how it compares to a mined stone in Lab Grown vs mined diamonds.

Lab Grown Diamonds come in the full range of fancy colors: yellow, blue, pink, green, orange, purple, gray, and even black, along with countless mixed hues, plus the near colorless whites most people picture first. Every color a natural diamond can show, a Lab Grown Diamond can show too.

Yellow and blue are the most straightforward, because those colors come directly from an element added during growth. Pinks, reds, and some greens usually involve a step after growth. Which brings us to the interesting part: how a lab actually puts color into a diamond.

Gem labs grade colored diamonds on the presence of color, the opposite of the familiar D-to-Z scale, which grades a white diamond on the absence of color (Source: GIA, 2026). Color is described by three things: hue (the color itself, such as blue or pink), tone (how light or dark it is), and saturation (how strong or vivid it is).

Those combine into a single grade. In order of increasing color strength, the grades run Faint, Very Light, Light, Fancy Light, Fancy, Fancy Intense, Fancy Vivid, Fancy Dark, and Fancy Deep (Source: GIA, 2026). The strongest, most saturated grades, Fancy Intense and Fancy Vivid, are the most sought after, but a softer Fancy is not a worse stone. It is a different, quieter look, and often the one people actually prefer on a hand.

A Lab Grown Diamond is graded with this same color vocabulary. IGI issues detailed reports on Lab Grown colored diamonds, and as of October 1, 2025, GIA describes Lab Grown Diamonds on Premium and Standard tiers rather than the full 4Cs (Source: GIA, 2025-10-01). If you want a fully detailed color grade on a Lab Grown stone, ask for an IGI report. Either way, the report is where you confirm the color and whether it was treated.

Color in a Lab Grown Diamond is set in one of two moments: while the crystal is growing, or after it is finished. Both are established, and both produce color that is genuinely part of the stone.

Color from growth (doping)

Lab Grown Diamonds are grown two ways: HPHT, which stands for high pressure, high temperature, and CVD, which stands for chemical vapor deposition. Introduce a trace element into that growth environment and the diamond takes on color from the inside. Boron produces blue. Nitrogen produces yellow, sometimes leaning orange. Nickel can produce green (Source: GIA, 2026). Those atoms sit inside the crystal lattice and absorb part of the light passing through, and what your eye sees is the color that is left. This is the same reason many natural diamonds are yellow or blue: the same elements, caught in the crystal as it formed underground.

Color from treatment (after growth)

Other colors are created or deepened after the diamond is grown, using the very same treatments applied to natural diamonds. HPHT treatment (a burst of high pressure and high temperature) can lift a brownish CVD diamond toward colorless or shift its color. Irradiation followed by careful heating, called annealing, builds color centers in the crystal. For a diamond grown with a little nitrogen, that process creates nitrogen-vacancy centers that produce pink to red, and related steps can yield blue or green (Source: GIA, 2026).

The important part: none of this is fake color. These treatments change the diamond's own crystal, not a surface layer, so the color runs all the way through the stone and stays put. A treated diamond is a real diamond whose color was created or strengthened by a known, repeatable process, and the same processes color a great many natural fancy diamonds too.

Yes, and it is worth being direct about this, because treatment sounds like a downgrade and it is not. Creating color with HPHT or irradiation is a standard, accepted part of the colored diamond trade, used on natural and Lab Grown stones alike, and it is disclosed on the grading report. A treated colored diamond is a real diamond. Its color is real color. The treatment simply describes how that color came to be.

The one thing to know is that treatment should always be stated, and on a proper report it is. Seeing a treatment noted on the paperwork is not a red flag. It is the process working exactly as intended, written down so you know what you are getting. Treated color is permanent under everyday wear. As with any treated colored diamond, natural or Lab Grown, tell your jeweler it is a treated stone before a repair that involves high heat, so they can protect it.

Start with the report. It will name the hue, give the grade from Faint to Fancy Vivid, and state whether the color is natural to the stone or the result of treatment. Confirm the report number on the grading lab's own website, the same step you would take for any diamond.

Then trust your eye. Hue and saturation are personal, and photos and screens shift color, so look at a fancy color stone in person or on video in normal light before you commit. A Fancy blue and a Fancy Vivid blue are both beautiful; one is simply louder than the other. Cut matters here too, because shape and proportions affect how strongly the color reads face up, and some fancy shapes concentrate color more than others.

On price, a fancy color Lab Grown Diamond costs well under a comparable natural fancy color diamond, which is genuinely rare, and that is what puts strong, saturated color within reach. Buy it as a love piece, something to keep and to mean something. No diamond, mined or Lab Grown, colored or colorless, is a financial asset, and colored stones attract that hope more than most, so it is worth saying plainly.

Where Stienhardt fits: Stienhardt.com sources Lab Grown Diamonds and hand-sets and finishes them into rings in NYC, direct to consumer, with in-person viewings by appointment only. If a colored stone is what you are after, you can browse our Fancy Color Lab Grown Diamonds, or start with our full range of Lab Grown Diamonds and choose the color that is yours.