Color with my animation process

"G" character is from my Logo
My main character , G & Dolphin are blue.
So, i could not use blue screen(cloth) background, I chose background in blue.
I had to think the background was going to blue in the final movie.
So, i have to find out what color i can use, and the final scene how to look like.
Red color would be good for both taking animation and editing animation.
I don't want to use too much red under the sea.
So, it was hard to find out what color would be good for my animation.