The fade. I zoomed in and noticed no pixels... so I took it for a gradient. Guess its an optical illusion with the bigger squares? If it is so, it looks great! Kudos for that! =D
Thank you :) What would you say is the problem with the background? Is it the fade (just to clarify I picked the colors out by hand and didn't use any gradient tools or stuff like that) or is it the question marks?
Ah I see. Each row of the bigger squares just has a different color which creates the effect of a gradient. It's actually just 5 colors all in all :)