Eh- sometimes it works, depends on your base color. I have dark brown hair with caramel highlights, and when it grows out a lil, it looks pretty trendy/cool, if I do say so myself
Not such a shock to the eyes, ya know?
Now, 3 inches of black roots on a bleached platinum head is NOT so hip. I think that's a pretty universal opinion unless youre Shakira, but even then it's pushing it...