Well, this is only a short explanation (i'm in a little bit of a hurry!) but my original interpretation of the rainbow diet (the pre-concieved one in my head) appears to have been completely wrong. But that's nothing a little internet research can't cure (...i hope :P)
According to the official website, Rainbow Diet is 'a nutritional breakthrough because it incorporates all the different colors: red, orange, yellow, green, blue, indigo and violet into the food we eat. Foods with a variety of colors have different healthy nutrients: vitamins, minerals, microelements, antioxidants, etc. We will identify the most useful foods for your condition and create one personalized nutritional plan, which will address not only your weight goals but your health concerns as well.'
Following that, it explains itself as a diet which incorporates all different 'colours' of food into it - so basically, you get a wide variety of foods with different nutritional qualities. This diet is also linked to cancer treatment.
This explanation is totally different to the idea that was already in my head. The idea I had of the rainbow diet was actually what is known as the 'Pro Ana Rainbow Diet', which means that 'Each day, only foods from a certain color group are allowed, such as yellow or red. Calories vary from 283 to 40 calories per day. The total amount of calories consumed per week is 696 calories. Most of the food consists of low calorie fruits and vegetables.'
An example of the pro-ana version of the diet would be:
Breakfast: ½ apple (40.5 cals)
Lunch: ½ apple (40.5 cals)
Dinner: 1 cucumber (24 cals)
Total: 105 cals
Breakfast: 1 banana (108.5 cals)
Lunch: 1 banana (108.5 cals)
Dinner: ½ cup corn (66 cals)
Total: 283 cals
Breakfast: ½ orange (31 cals)
Lunch: ½ orange (31 cals)
Dinner: 1 carrot (26 cals)
Total: 88 cals
Breakfast: ½ cup strawberries (21.5 cals)
Lunch: ½ cup strawberries (21.5 cals)
Dinner: ½ red pepper (16 cals)
Total: 59 cals
Breakfast: 10 blueberries (8 cals)
Lunch: 10 blueberries (8 cals)
Dinner: 10 raspberries (24 cals)
Total: 40 cals
Breakfast: ½ cup grapes (57 cals)
Lunch: ½ grapes (57 cals)
Dinner: 1 cup lettuce (7 cals)
Total: 121 cals
Week total: 696 cals
Did that answer your question...(sort of)?