Three ways you can get a request. First person to answer correctly (or come close for the first one) gets that request. You can answer multiple questions, but you'll only get one request :) Hopefully this is actually entertaining:
1: Why is Yuri angry? - full color/shaded request
2: What signature part of Yuri's design/look is missing? - Color request (not fully shaded - like this drawing)
3: What anime reference is hidden in the drawing and what's it from? - Color request (not fully shaded)