Tomatoes may be the most visually diverse crop in the garden. Walk through a row of heirlooms at peak ripeness and you’ll find deep reds, bright oranges, pale yellows, green-when-ripe types, and even dusky purple fruit—some striped, others washed with a faint blush. It’s part of what makes growing tomatoes so satisfying. But while tomato colors feel almost endless, the way tomatoes get those colors is surprisingly straightforward—and often misunderstood.
In this article, we’ll explore the science behind tomato colors. Don’t worry—this isn’t high-school chemistry. It’s closer to kindergarten color mixing. By the end, you’ll understand how just a few simple pigments shape not only a tomato’s appearance, but often its flavor and even its nutritional profile. So join me as we look at how tomatoes get their colors.
The Base Pigments: Where Tomato Color Begins
At its most basic level, tomato color begins in the flesh. As tomatoes ripen, they accumulate carotenoids—naturally occurring pigments responsible for many of the red, orange, and yellow hues we see in fruits and vegetables.
Big Elmer's bright orange hue is but one color in the vast rainbow of heirloom tomatoes.
You probably already know that red tomatoes contain lycopene. That familiar deep red color develops as lycopene builds up during ripening. Orange tomatoes, by contrast, often accumulate more beta-carotene, giving them their bright tangerine tone. Yellow varieties produce very little lycopene, and white tomatoes almost none at all. Without that dominant red pigment, the remaining carotenoids—present in much smaller amounts—become visible, giving the fruit its lighter yellow or pale appearance.
At this stage, tomato color is relatively straightforward. The specific carotenoids stored in the flesh determine the fruit’s base hue. But as we’ll see next, that’s only the first layer of the story.
The Role of the Skin in Tomato Color
The next time you’re at a party and want to impress someone, casually mention that red and pink tomatoes are actually the same color—on the inside. I'll be honest, I was pretty far into my gardening life before I learned this. The difference isn’t in the flesh at all. Both red and pink tomatoes contain lycopene and develop more or less the same red internal color as they ripen.
What changes is the skin.
Tomato skin can be either clear or yellow. When a tomato with red flesh has yellow skin, the fruit appears red. When that same red flesh is covered with clear skin, the fruit appears pink. The epidermis acts like a thin optical filter over the flesh beneath it, subtly softening or warming the color depending on whether the skin is clear or yellow.
Cherokee Purple is famous for its dusky purple tone. But with just one mutation, this moody purple tomato can change to a warm mahogany.
One of the best illustrations of this phenomenon is Cherokee Chocolate, which arose as a spontaneous mutation of Cherokee Purple in the garden of Craig LeHoullier many years ago. In terms of growth habit and fruit arrangement, the two are essentially identical—the only meaningful difference is the skin color. Add yellow skin over Cherokee Purple’s famously dusky flesh, and the fruit shifts to a rich mahogany brown. Remove that yellow filter, and the same flesh reads as purple.
It’s a simple genetic change—but a striking visual one.
Chlorophyll Retention: The Third Layer of Color
So far, we’ve talked about pigments in the flesh and filters in the skin. But that still leaves an obvious question: why is the flesh of varieties like Cherokee Purple so dark in the first place?
The answer has to do with a pigment most ripe tomatoes are supposed to lose—chlorophyll.
All tomatoes begin green. In typical red varieties, chlorophyll breaks down as the fruit ripens and lycopene accumulates, allowing the red pigment to dominate. But in some heirloom types, that breakdown is incomplete. A portion of the green chlorophyll remains in the flesh even as red lycopene develops.
The interiors of these Noire de Cosebeouf tomatoes reveal the truth—purple heirloom tomatoes are actually the result of red lycopene mixing with green chlorophyll to create a dusky brown flesh color that, when covered with clear skin, translates as purple.
Red and green together don’t look red. They look brown, dusky, or what we often call “purple.”
When that darker flesh is covered with clear skin, the fruit takes on the classic purple hue of varieties like Cherokee Purple. Add yellow skin instead, and the same internal color shifts toward mahogany brown—as we saw with Cherokee Chocolate.
Are “Purple” Tomatoes Really Purple?
Many people assume that heirloom varieties like Cherokee Purple get their color from anthocyanins—the same antioxidant pigments that give blueberries their deep purple tones.
In traditional heirloom tomatoes, that isn’t the case.
Tomato plants possess the genetic machinery needed to produce anthocyanins, but in most cultivated varieties that machinery is effectively switched off in the fruit. That is, until recently. Utilizing wild tomatoes, breeders were able to introduce genes that override the usual suppression, producing tomatoes that accumulate anthocyanins.
These Wooly Kate tomatoes carry unique purple skin coloration, made possible by wild tomato genes that permit anthocyanin production in the epidermis.
The catch: it's primarily in the skin. Slice one open and you’ll find the interior still reflects the familiar reds, oranges, or yellows of standard carotenoid pigments. Still, these tomatoes are a sight to behold. And over time, they've been bred to have a flavor to match their beauty.
We’ll take a closer look at how those modern purple tomatoes were bred—and how they differ from heirloom “purple” types—in a dedicated post. There, we'll also tackle the ground-breaking science, and consumer concerns, surrounding the new genetically modified "Purple Tomato".
Putting It All Together
At this point, we’ve discussed three primary layers of tomato color:
- The base flesh color (carotenoids like lycopene and beta-carotene)
- The skin (clear or yellow)
- Chlorophyll retention (the greenflesh, or gf, trait)
The graphic below summarizes how these layers interact to form the rainbow of colors we commonly see in heirloom tomatoes.
The wide range of colors seen in heirloom tomatoes are possible thanks to the combination of just a few simple variables: flesh color, skin color, and chlorophyll retention.
Each column begins with a base flesh color—red, orange, yellow, or white. From there, two factors modify what we ultimately see:
- Skin color, which subtly shifts tone
- Chlorophyll retention, which deepens and shifts the hue
Let’s walk through each one and give some examples.
Red Flesh
When red flesh (rich in lycopene) is covered with yellow skin, the fruit appears red. With clear skin, the same flesh appears pink.
If the variety also carries the gf trait, retained chlorophyll darkens the red flesh to produce what we often call “purple” or black tomatoes.
Red fleshed tomatoes can present as a number of different colors, depending simply on their skin color and the presence or absence of chlorophyll in the mature fruit.
Examples:
- Red: Rutgers, Marglobe, Amish Paste, Tommy Toe
- Pink: Pink Brandywine, Mortgage Lifter, German Pink
- Purple/Black: Cherokee Purple, Black Krim, Black Cherry
- Brown: Chocolate Cherry, Chocolate Stripes, Chocolate Pear
As you can see, the same underlying flesh color can produce a wide range of colors.
Orange Flesh
Orange tomatoes accumulate higher levels of beta-carotene.
With clear skin, the fruit appears bright orange. Yellow skin deepens the tone toward a richer tangerine shade.
If chlorophyll is retained, the orange flesh can take on earthy, muted tones—sometimes described as coppery or bronze.
Examples:
- Orange: Jaune Flamme, Big Elmer, Orange Strawberry
- Bronze (gf influence): Thornburn's Terracotta
Yellow & White Flesh
Yellow and white tomatoes both contain little to no lycopene. The difference is largely a matter of degree: yellow types accumulate modest amounts of other carotenoids (like beta-carotene), while white types have extremely low overall carotenoid concentrations.
With clear skin, yellow-fleshed tomatoes appear lemon to golden, while white-fleshed types remain pale ivory. With yellow skin, both warm slightly in tone.
If chlorophyll is retained at maturity, these same fruits shift toward green: yellow-fleshed varieties may appear lime or chartreuse, while white-fleshed types take on a softer mint or translucent green cast.
When lycopene is absent, tomato color is shaped by the remaining carotenoids and the presence (or absence) of chlorophyll—producing hues that range from deep orange to lime green to ivory white. Credit for white tomato image.
Examples:
- Yellow: Yellow Pear, Dr. Wyche's Yellow, Dixie Golden Giant
- White: White Cherry, Great White
- Lime/Mint Green: Green Zebra, Aunt Ruby's German Green
What this illustrates is that tomato color isn’t controlled by dozens of unrelated pigments. Instead, a small number of interacting traits—flesh pigments, skin color, and chlorophyll retention—combine to produce an astonishing range of visible outcomes.
And we haven’t even touched patterning yet.
Pigment Modifiers: When Color Isn’t Uniform
Up to this point, we’ve treated tomato color as if it develops evenly across the fruit. In reality, that’s rarely the case. Several genetic traits—and even sunlight itself—can modify how pigments appear, creating patterns that range from subtle to dramatic.
Light-Induced Anthocyanins
In tomatoes that are capable of producing anthocyanins, pigment development is strongly influenced by light. Sun-exposed portions of the fruit accumulate deeper purple or blue tones, while shaded areas may remain red, yellow, or green beneath.
The Alice's Dream tomato produces dark purple pigment in the sun kissed portions of its skin. When the fruit is shaded, anthocyanins are not produced, allowing its beautiful striped pattern to shine through.
This is why some modern “purple” tomatoes show color concentrated on the shoulders or sun-facing side. The pigment isn’t distributed evenly because anthocyanin production is light-responsive. Move the fruit into shade, and the intensity decreases.
In traditional heirloom purple tomatoes, this effect does not occur because anthocyanins are not present in the fruit at all.
Uniform Ripening and Green Shoulders
Not all color differences are dramatic. Some are subtle—and in heirloom tomatoes, often beautiful.
Many modern commercial tomatoes carry a mutation known as uniform ripening, which reduces chlorophyll in the shoulders of immature fruit. This allows the fruit to turn evenly red as it matures, creating the consistent appearance favored in large-scale production.
Heirloom varieties often lack this mutation. As a result, they retain more chlorophyll near the stem end during early fruit development. When ripening begins, those shoulders may not fully degrade their chlorophyll, leaving behind darker or green-toned areas even at maturity.
Its beautiful green shoulders are what have made Cherokee Purple a household name. The sketched green starburst pattern surrounding the stem is widely portrayed in artwork featuring this popular heirloom.
Cherokee Purple is perhaps the most beloved example of this trait. Its fruit frequently display green shoulders marked by darker streaks that radiate outward from the stem in a subtle starburst pattern. The effect is so distinctive that it has become part of the variety’s identity—often romanticized in watercolor paintings and seed catalog illustrations alike.
What looks like artistic flair is, in reality, a difference in chlorophyll breakdown and early chloroplast development.
It isn’t a flaw. It’s genetic diversity.
And in some cases, that retained chloroplast capacity during early development may even influence sugar production—adding another layer to the conversation about flavor.
Striping in Tomatoes
Striping adds another layer of complexity. While the visual effect is striking, the underlying biology is not fully understood. What we do know is that striping reflects regional differences in pigment accumulation and breakdown as the fruit develops.
In some striped varieties, chlorophyll persists in certain bands longer than in surrounding tissue. In others, carotenoid accumulation varies across the surface. These localized differences create alternating zones of color—but the pigments involved are the same ones we’ve already discussed.
Chocolate Stripes tomatoes feature unique, striped exteriors. Because this variety carries the greenflesh allele, chlorophyll is retained in the striped sectors giving them a bold green color that contrasts beautifully against their chocolate brown base hue.
The appearance of stripes can also interact with other genetic factors. For example, in varieties that carry the greenflesh (gf) trait, areas that retain chlorophyll may remain distinctly green even at full ripeness. In striped types without gf, those same regions typically lose chlorophyll and instead appear yellow or gold as underlying carotenoids become visible.
Striping, then, is not a new pigment pathway—it is a pattern layered over existing ones. Its final appearance depends on which other color traits are present in the plant.
Bi-coloring
If striping alters the surface, bicolor tomatoes reshape the interior.
Varieties like Gold Medal, Hillbilly Potato Leaf and other classic bicolors begin with a yellow base. As the fruit ripens, lycopene does not accumulate evenly throughout the flesh. Instead, red pigment develops in streaks or marbled sections—often radiating outward from the blossom end.
The result is a fruit that appears golden from the outside but reveals red flames when sliced open.
Big Rainbow tomatoes are often touted to be one of the best tasting bicolor tomatoes. With rich, orange exteriors and vibrant red blushing, they more than earn their name.
At the biochemical level, nothing new has been added. Bicolors still rely on the same carotenoids—primarily lycopene and beta-carotene. What changes is where and when lycopene accumulates during ripening. Some tissues convert fully to red; others remain in their lower-lycopene yellow state.
And like striping, bicolors can interact with other traits. A bicolor carrying chlorophyll retention—like Ananas Noir for example—may show deeper internal shading. One with clear skin may appear softer and more pastel from the outside. The layers stack.
Do Tomato Colors Affect Flavor?
Yes—but not in the ways you might expect.
Yellow tomatoes, for example, are not inherently less acidic. Red tomatoes are not automatically more acidic. Color alone doesn’t determine a tomato’s pH, despite how often that myth is repeated. (We take a closer look at the acidity question in this post.)
Beam's Yellow Pear tomatoes feature a cheerful yellow color and a unique form, giving them a true pear-like appearance.
That said, the pigments that give tomatoes their characteristic colors can have subtle effects on flavor and nutrition. Carotenoids influence aroma compounds, chloroplast development can affect sugar production, and genetic backgrounds often cluster certain flavor traits with particular color types.
The relationship isn’t simple—but it is fascinating.
We’ll explore that interplay in much greater detail in our next post: How the Color of a Tomato Influences Its Flavor.
Final Thoughts
The next time you slice into a tomato—or admire one on the vine—you’ll know there’s more at work than simple color. Beneath every red, pink, yellow, or “purple” fruit lies a layered story of pigments, filters, and ripening patterns interacting in subtle ways. What once looked like endless variation turns out to be a handful of beautifully coordinated biological processes. And somehow, knowing that only makes them more remarkable.
Want to grow the rainbow? Check out our colorful selection of heirloom tomato seeds and find vibrant, delicious varieties to suit both your aesthetic and tastes.
