Sweet potatoes are orange because of beta-carotene, the same pigment that gives carrots and apricots their color. A raw orange-fleshed sweet potato contains about 13.1 mg of beta-carotene per 100 grams, making it one of the most concentrated natural sources of this pigment. But not all sweet potatoes are orange. The color depends entirely on which pigments the plant’s genes tell it to produce and store.
Beta-Carotene Creates the Orange Color
Beta-carotene belongs to a family of pigments called carotenoids. These molecules absorb blue and green wavelengths of light and reflect back the warm yellow, orange, and red wavelengths you see. The more beta-carotene packed into the flesh, the deeper the orange. Orange-fleshed sweet potatoes contain roughly 15.5 mg of total carotenoids per 100 grams, and beta-carotene accounts for about 85% of that total.
The pigment molecules are stored inside tiny structures within plant cells called chromoplasts. These compartments don’t just hold beta-carotene loosely. They form stable complexes where the pigment binds to fats and specialized proteins, creating a kind of storage scaffold that prevents the beta-carotene from breaking down. This is why the orange color stays vivid even as the root grows underground for months.
Genetics Determine Which Color a Sweet Potato Gets
Sweet potatoes come in white, cream, yellow, orange, and deep purple varieties. The color depends on which pigment-production genes are active. In orange varieties, two key enzymes drive the chemical assembly line that builds beta-carotene. One converts a precursor molecule into lycopene (the red pigment found in tomatoes), and another reshapes lycopene into beta-carotene. The more active these enzymes are, the more orange pigment accumulates.
There’s also a gene called the Orange gene (IbOr) that controls how much beta-carotene the root actually stores. Even if a sweet potato produces beta-carotene, it won’t look intensely orange unless this gene triggers the formation of enough chromoplast storage structures to hold it all. When researchers introduced the Orange gene into plants that normally don’t accumulate carotenoids, those plants developed large pigment-storing compartments and turned visibly orange.
Purple sweet potatoes use an entirely different pigment system. Their color comes from anthocyanins, water-soluble compounds related to the pigments in blueberries and red cabbage. Purple varieties produce primarily two types of anthocyanins, peonidin and cyanidin derivatives, while containing very little beta-carotene. Orange varieties flip that ratio: high carotenoids, minimal anthocyanins. White-fleshed sweet potatoes produce low levels of both.
Orange Wasn’t Always the Default
If you live in the United States, you probably think of sweet potatoes as orange, but that’s a regional preference. In much of East and Southern Africa, consumers historically preferred white or yellow-fleshed varieties with a drier, starchier texture. Orange-fleshed sweet potatoes tend to have higher moisture and lower dry matter content, which many people found watery and unappealing.
Starting in the mid-1990s, agricultural researchers began promoting orange-fleshed varieties in sub-Saharan Africa because their high beta-carotene content could help address widespread vitamin A deficiency. The challenge was breeding varieties that had both the nutritional benefits of orange flesh and the dry, firm texture local consumers wanted. By 2004, breeders recognized they needed to develop varieties specifically adapted to African growing conditions and taste preferences rather than importing cultivars from other regions. Over the following decade, 40 new orange-fleshed varieties bred in Africa were released across nine countries. By 2015, orange-fleshed sweet potatoes made up 32% of all sweet potatoes grown in Mozambique.
In the U.S., orange varieties like Beauregard and Jewel dominate grocery stores largely because of similar breeding choices made decades earlier, prioritizing sweetness, moisture, and bright color for the American market.
Why Orange Means High Vitamin A
Beta-carotene isn’t just a pigment. Your body converts it into vitamin A, which is essential for vision, immune function, and cell growth. The deeper the orange, the more beta-carotene, and the more vitamin A potential.
A single baked sweet potato with skin provides about 1,403 micrograms of vitamin A activity, which is 156% of the daily value for adults. That makes one sweet potato enough to exceed your entire day’s requirement. For comparison, carrots contain a similar concentration of beta-carotene on a dry-weight basis (roughly 17 to 21 mg per 100 grams dry weight for both vegetables), but sweet potatoes deliver a larger serving size per sitting, so you typically get more total beta-carotene from a whole baked sweet potato than from a typical portion of carrots.
Cooking actually helps. Heat breaks down cell walls and the chromoplast structures that hold beta-carotene, making the pigment easier for your digestive system to absorb. Eating sweet potatoes with a small amount of fat improves absorption further, since beta-carotene is fat-soluble and needs to dissolve in dietary fat to cross your intestinal lining efficiently.
Growing Conditions Affect Color Intensity
While genetics set the ceiling for how orange a sweet potato can be, environmental conditions during growth influence whether it reaches that ceiling. Drought stress causes pigment breakdown in sweet potato plants, visibly shifting leaves from deep green to yellow-green as both chlorophyll and carotenoids degrade. Excessive waterlogging produces a subtler but similar effect, reducing pigment concentrations through persistent stress on plant tissues.
After harvest, storage conditions matter too. Dried orange-fleshed sweet potato retains about 66 to 67% of its original carotenoid content, with even greater losses at low humidity. For fresh sweet potatoes kept in your kitchen, cool and dark storage slows carotenoid breakdown, preserving both the color and the nutritional value. Heat, light, and oxygen all accelerate degradation of beta-carotene over time.