looking for original m/m fic

[Guest lebee]

I'm looking for a fic where there is vampires. they sort of rule the world and they have sort human by the taste of their blood with color. Each human have an id with a color and black is the worst taste and white the better. The hero has a black color and it turn out it's wrong. So he get chase after by vampires and i remember at some point ther is an auction with lot of vampire who came for him.

I hope someone can remember it by my description and help me.

[Guest Gwengwel]

Undesirable by Velvet Mace

http://original.adult-fanfiction.org/story.php?no=600098428