WoWInterface - Cooldown:SetSwipeTexture() help

This code should show a blue ring growing longer in a circle.
This is based off the runebar code in 7.2.5 for deathknights.
Be sure to have omniCC turned off since this breaks the animation.

But for some reason the ring is coming in as dark grey. I must be missing something.

Code:

DKTestScaleFrame = DKTestScaleFrame or CreateFrame('Frame')

DKTestScaleFrame:ClearAllPoints()

DKTestScaleFrame:SetPoint('LEFT')

DKTestScaleFrame:SetSize(100, 100)



DKTestScaleFrame:SetScale(1)



DKTestFrame = DKTestFrame or CreateFrame('Frame', nil, DKTestScaleFrame)



DKTestFrame:ClearAllPoints()

DKTestFrame:SetPoint('CENTER')

DKTestFrame:SetSize(100, 100)



DKTestTexture = DKTestFrame:CreateTexture(nil, 'OVERLAY')

DKTestTexture:SetAtlas([[DK-Rune-CD]])

DKTestTexture:SetAllPoints()





CooldownTestFrame = CooldownTestFrame or CreateFrame('Cooldown', nil, DKTestFrame, 'CooldownFrameTemplate')



CooldownTestFrame:ClearAllPoints()

CooldownTestFrame:SetPoint('CENTER', DKTestFrame, 'CENTER')



CooldownTestFrame:SetReverse(true)

CooldownTestFrame:SetSwipeTexture([[Interface\PlayerFrame\DK-Frost-Rune-CDFill]])

CooldownTestFrame:SetEdgeTexture([[Interface\PlayerFrame\DK-BloodUnholy-Rune-CDSpark]])





CooldownTestFrame:SetDrawEdge(true)

CooldownTestFrame:SetDrawBling(false)

CooldownTestFrame:SetHideCountdownNumbers(true)



CooldownTestFrame:SetSize(100, 100)





CooldownTestFrame:SetCooldown(GetTime(), 10)