I detest the idea that only one kind of coloring is "okay" and deserving of a smiley face. Just... NO.
Sometimes you *need* to color outside the lines, or use colors that don't "make sense", or leave a lot of white space. I believe this sort of "you must conform" attitude damages young artists and stunts their creativity.
I first saw it on Pinterest, and it made me so mad... Just say NO to the coloring rubric!