OK please be descriptive

http://fbgods.com/layouts/images/dbz/dbz_r1_c1.jpg

Guys can you tell me how they changed the background of the image into blue without affecting the pics of the character a single bit. The original pic wasn't blue. Please be descriptive

It'd be much easier to see what you are talking about if we could see the original image.

that is the original
If you just look hwo everythign behinf the characters are blue that's what I mean. How did he make teh background blue like that without affectign any of the characters. and please tell me what blending he used

Most likely, he carefully cut around the characters and adjusted the hue,saturation to make the background of the pic blue. He then stuck the image back in and hey presto, it's a blue background, in all it's detail, and the anime character the same colour. It could have also been done using layer masks, he just painted around the character, in the mask layer, and then set hue,saturation to a blue colour. Could be another way, but that would get a good result.