I think it looks great!

Hypnotoad is one of my finace's favorite Futurama characters.
Were you asking about how you should fill in the background?
I think it's too late to color the background since you don't want to accidentally mess up your finished stitches
Sometimes I just like to do a half stitch for the background, but full stitches always looks the nicest.
I usually just leave the background the way it is and iron the whole thing out and put it in a frame.
Finished stitchings always look even better in a frame in my opinion