Thank you for this Heyy. That's a nice and easy way of looking at it.
I tend to go by, feed your child a rainbow everyday. And try to give LO at least one piece of food of each colour. (I throw in some other colours like fish from time to time too.)
E.g.
Red - Apple, red meat, red lentils, strawberries, raspberries etc.
Orange - Oranges, orange peppers, carrots, sweet potato, apricots etc
Yellow - Banana, cheese, egg, pineapple, sweetcorn etc
Green - Peas, broccoli, kiwi, grapes etc
Blue/Indigo/Violet - Blueberries, plums, purple cabbage, aubergine (eggplant)