this is a broccoli drawing for part of the banner in a thread i hang out in.

i'm still a total newbie to the world of digital art, so would anybody here mind critiquing my piece? i'm not looking for somebody with specific master expertise on broccoli dynamics and proportions, but i'd prefer if you guys could mainly critique the coloring, and perhaps give me some tips on coloring/shading/blending on digital canvasses? thanks :]
my deviantart i made just a little while ago..