Froot Loops

Froot Loops is a brand of fruit-flavored, sweetened, breakfast cereal produced by Kellogg's. It comes in six colors: red, blue, yellow, green, orange, and purple.

In The Big Bang Theory
Howard Wolowitz seems to like this cereal, since this is what his mother makes him for breakfast. this was also his astronaut nickname by Mike Massimino after his mother yells at him about his cereal, much to Howard's dismay.