[Rilgamon]

For a quick solution you can remove the target part and it will just color player and focus.

["target"] = {
        ["name"] = "TargetFrame",
        ["back"] = "TargetFrame",
        ["x-offset"] = -104,
        ["y-offset"] = 60,
        ["x-offset2"] = 6,
        ["y-offset2"] = -22,
    },

For a longer solution replace the 'SetVertexColor' line with

if(not UnitIsPlayer(unit)) then
                    uf['unitClassColorBack']:SetVertexColor(0, 0, 0, 0)
                else
                    uf['unitClassColorBack']:SetVertexColor(col['r'], col['g'], col['b'],1)
                end

NPC are mostly warriors or mages. Thats a generic value for them