[Ketho]

To expand on SDPhantom's post, you can additionally mask the texture

local genders = {nil, "male", "female"}
 
hooksecurefunc("UnitFramePortrait_Update",function(self)
    if self.portrait and UnitIsPlayer(self.unit) then
        local _, race = UnitRace(self.unit)
        local sexID = UnitSex(self.unit)
        local atlas = GetRaceAtlas(race:lower(), genders[sexID], true)
        self.portrait:SetMask("Interface\\CharacterFrame\\TempPortraitAlphaMask")
        self.portrait:SetAtlas(atlas)
    end
end)