By just eating the rainbow which includes eating fruits and vegetables of different colours each day, it creates the colour diet.

Plant which contains different pigments of phytonutrients, which gives them their color. Different colored plants are linked with higher levels of specific nutrients and various other health benefits.

By eating more vegetables and fruits it is always good idea to focus on eating various kinds of colors as it will increase the intake of different nutrients to benefit from various areas of your health.

As there are many benefits of phytonutrients, as its difficult to perform randomized controlled trails and the most rigorous type of research proves their efficacy. Most of the research is based on the population level intakes and disease risk.

Most of the studies shoes the benefits from regularly eating colorful fruits and vegetables with no risks. By getting a variety of color in the diet, we're giving our body an array of vitamins, minerals and phytochemicals which is beneficial for our health.

Sources: https://www.healthline.com/nutrition/eat-the-rainbow#The-colors