I was happy with the contrast that this color-scheme provided my drawing: rich and lively in the front with deep saturated colors, bleeck and depressing colors in the back. The eye tends to only see what's in the saturated parts, and that's why this contrast was so fitting for my concept of optical illusion: only if you look a little further, you start seeing what's wrong. 

However the blue waterfall was itching my brain because it was asking way too much attention since there are no other blues in the drawing. So after some contemplating I deleted it to finalise my drawing. I was now finished and ready to submit my final drawing!