Eating the Rainbow: Why Variety Matters

Why do different colours matter?

Plant foods contain thousands of naturally occurring compounds called phytonutrients, or phytochemicals. Some contribute to their colour, while others have antioxidant, anti-inflammatory and other biological properties (3).

Different colours tend to provide different combinations of phytonutrients (4):

Red — Contains phytonutrients such as lycopene, a type of carotenoid with antioxidant properties that protects cells from oxidative stress. Lycopene is abundant in tomatoes and watermelon. Other red foods including strawberries, red grapes and red capsicum, provide different beneficial phytonutrients.

Orange and yellow — Rich in carotenoids such as alpha-carotene, beta-carotene, lutein and zeaxanthin. Alpha- and beta-carotene can be converted into vitamin A, which supports normal vision and immune function, while lutein and zeaxanthin are particularly important for eye health. Examples include carrots, pumpkin, sweet potato, corn and yellow capsicum.

Green — Provides a range of beneficial plant compounds, including chlorophyll, carotenoids and dietary nitrates, alongside nutrients such as folate and vitamin K. Some of these compounds can support healthy blood vessel function. Examples include spinach, broccoli, kale and avocado.

Blue and purple — Rich in anthocyanins, a type of flavonoid with antioxidant and anti-inflammatory properties. Anthocyanins have been associated with cardiovascular and metabolic health benefits. Examples include blueberries, blackberries, purple grapes, eggplant and purple cabbage.

White and brown — Contains a range of phytonutrients, including organosulfur compounds such as allicin, which is found in garlic and has been studied for its potential cardiovascular and antimicrobial properties. Examples include garlic, onions, cauliflower, mushrooms and potatoes.

These categories aren't absolute—each plant food contains its own combination of phytonutrients, vitamins, minerals and fibre. Eating across the different colours is simply a practical way to encourage greater variety in your diet.

How can you eat more variety?

Some simple strategies to increase your variety include:

• Look at your usual colours. Are there colours you rarely include?
• Add a different colour. Try berries at breakfast, leafy greens at lunch or carrots and capsicum with dinner.
• Rotate your produce. Swap one or two of your usual fruits or vegetables for something different each week.
• Think beyond fruit and vegetables. Herbs, spices, legumes, wholegrains, nuts and seeds also contribute to plant diversity.
• Try something new. Experiment with a new plant food or a different variety of something you already enjoy.

Fresh, frozen and canned options can all help increase variety. You don't need every colour at every meal—focus on building variety across your day and week.

Take-home message

“Eating the rainbow” is a simple way to encourage greater variety in your diet. Rather than focusing on one particular “superfood”, regularly include a range of different fruits, vegetables and other plant foods.

When it comes to plants, variety matters.