Not yet. In the future, yes. But it will probably be insanely high. Something only the richest say 10% can afford. Don't want everyone having custom username colors, or it may make staff too indistinguishable.

When it comes, there will be a predefined set of 6-8 colors or so you can pick from.

admins
donors
snowflakes
global mods
mods
available for picking
available for picking
available for picking
available for picking
available for picking
available for picking
available for picking


Those colors are tentative though. I might change them if they look too similar to the staff titles.