I am blue, I am number 1, I am friends with Percy and Toby and you’ll for sure hear me when I come. Who am I?

Question

From far away I may appear blue.
A little closer and you'll see green and white too.
When you look much closer you will see,
that I contain all the colors you can see.
I'm held aloft by a very weak force;
One that I also help to enforce.
What am I?