Well, color can impact a lot beyond it's borders. If the drawing style doesn't agree with me, I wouldn't read it in b/w because the drawing would be so apparent, but in color the colors can detract from the negative aspects of the drawing style. So, color can impact a lot. Normally I read manga in b/w, though. Graphic novel/comic-wise, though, I prefer color. I dunno, I'm weird, lol. I differentiate between the two, even though they basically are the same. I think the thing is, I like glossy pages to be color and graphic novels/anthologized comics more often than not have glossy pages and, thus, color as well. While manga is mostly toned and I'm just fine with that (as long as the illustration style is something I can appreciate).