I think the term that wouldn't bother anyone is "rare." What colors are rare to see in a tail? I don't think I've seen a pure white tail. My guess is that white might be more see through, so while it's a nice color (I'm all about winter white! And anytime whitel,) it's not a practical one.

I also notice that many mermen tend to lean towards greys, blacks and more earthy tones. Of course many choose bright colors too, but it seems they also choose natural colors more often then mermaids do.

It's also not often that I see a really red tail. Women usually love to wear red (the red dress, red bikini, and red lipstick have very intense feminine symbolism), so it's interesting that red is not common in tails. My theory is that mermaiding brings out the softer more girly feminine side, so pinks and bright flowery colors are often go tos. Though I would love to see a sexy vavoom Jessica Rabbit style tail!

It seems there is consensus that blue is one of the most common colors. I think most of us mermaids always love blue because it is the color of the ocean. It's one of my favorites for sure! But I wouldn't choose it for a tail because I see blue tails have a tendency to disappear into the blue of the water in photos. The contrast of pinks and oranges against the big blue is more dynamic.