Ya sure, you can get a few custom colors using qualities 8-14, but I know how to get ANY color of the rainbow using a simple coloring technique blizzards been using since Warcraft!

Take the name of any item, Worn Shortsword for example. In the beginning of the name, we put the following:

|cFFXXXXXX

XXXXXX being a color code from Web Color Chart - Hexadecimal - by VisiBone

At the end of the name, put |r



So, our item should look something like like:

|cFFFF0000Worn Shortsword|r

(The color code is red)

And ingame:



In HeidiSQL: