Try this.
lua Code:
local function SetFont(obj, font, size, style, alpha, r, g, b, sr, sg, sb, sox, soy, spacing)
obj:SetFont(font, size, style)
if sr and sg and sb then obj:SetShadowColor(sr, sg, sb) end
if sox and soy then obj:SetShadowOffset(sox, soy) end
if r and g and b then obj:SetTextColor(r, g, b) end
if alpha then obj:SetAlpha(r) end
if spacing then obj:SetSpacing(spacing) end
end
local f = CreateFrame("Frame")
f:RegisterEvent("ADDON_LOADED")
f:SetScript("OnEvent", function()
SetFont(GameFontBlack, font, fontsize, outline, 1, 1, 1, 1, 0, 0, 0, 0, 0);