I second what MAC_Whore said. I wear NC15 everything, and I'd read that you're supposed to wear a concealer one shade lighter than your skin, but I was like, "MAC doesn't make NC-Ghost White!" When I went to the MAC store, the MA actually told me to get NW15, because the dark circles under my eyes are especially noticeable due to the fact that I'm so pale (my words, not hers). She was right. The NW shade really cut down on the bluish circles. I like it for covering blemishes, too. So perhaps try your shade, but in NW?