"Even when I'm hogging the whole top row I can't seem to make it blend! WHERE did those little lines come from?"

i guess i cant see any little lines. or maybe you mean the very slight color distortion at that one edge? i would consider the top row blendy, anyway.

i am wondering, though, if you might be seeing this occasional browser "bug". sometimes images get little gaps between them in some browsers. a reload might fix it, other times it just kinda goes away. needless to say, it *really* goes away when the completed level is merged into one image. fyi/fwiw/etc.