[Ekaterina]

Logic,

I think you're using the wrong method to try and change the background colour.

Try:

local class = select(2, UnitClass("player"))   -- get the player class
local classColour = CUSTOM_CLASS_COLORS[class] or  RAID_CLASS_COLORS[class] -- get the class colour
local gradientEndColour = { 
	r = 0, 
	g = 0, 
	b = 0, 
	a = 1,
} -- define the 2nd colour for the gradient

self.bg:SetGradientAlpha("VERTICAL", gradientEndColour.r, gradientEndColour.g, gradientEndColour.b, gradientEndColour.a, classColour.r, classColour.g, classColour.b, self.bg:GetAlpha()))  -- To reverse the gradient, swap the gradientEndColour and classColours.
self:SetBackdropBorderColor(classColour.r, classColour.g, classColour.b, self.bg:GetAlpha()))

The source for this was the wonderful Seerah, from the below discussions.

http://www.wowinterface.com/forums/s...ad.php?t=27572
http://saanlem.wowinterface.com/foru...ad.php?t=40240