Birthday Present 1 WIP (With some color this time) (Patreon)

I need your help with this one, I'm not really sure how to do color backgrounds and I'm struggling a bit, does this look good? or is it too much color? I'm used to doing just white backgrounds or just grey with some details here and there, tried doing that but with different colors but I'm not sure if it looks good or not, let me know what you think and if you have any references I could look up to it would be great, other artists that I've seen draw what should be behind her characters but I'm not sure what to do here, a wall? not sure what I should do, heeeeeelp, also don't mind the colors, they are just the base, I haven't done any shadows or lights hehe