For the background, I was thinking of a light blue, almost translucent background with tiny white question marks on it. But any attempt just doesn't look right. I can't really place on what is wrong with it and how I should improve. I was wondering if there is a better way to approach making color backgrounds or just backgrounds in general?
Edit: My apologies I should've been more clear. I have looked at color selection and color psychology. I just meant more, I think there is something lacking with my blending and implementation rather than the actual selection of the color.