[p3lim]

Or this:

for _, method in pairs({'RandomBGButton', 'Arena1Button', 'Arena2Button'}) do
    local bu = BonusFrame[method]
    bu.SelectedTexture:SetDrawLayer("BACKGROUND")
    bu.SelectedTexture:SetTexture(r, g, b, .2)
    bu.SelectedTexture:SetAllPoints()
end

I do exactly this for disabling the textures for the stock OverrideActionBar in my action bar addon:
https://github.com/p3lim-wow/pAction...rd.lua#L58-L75