Help with rank script?

I made a somewhat more of an advanced script and I got everything to work except for color updating when you get a rankup or something. So How could I make the color update with this code?

--Place the script named Rank Script in Workplace
--Place the BillboardGui named Rank in ServerStorage
--Created by centerspell
ranks = {
    [243] = Color3.new(255/255, 255/255, 255/255),
    [244] = Color3.new(255/255, 0/255, 0/255),
    [245] = Color3.new(139/255, 0/255, 0/255),
    [246] = Color3.new(255/255, 255/255, 0/255),
    [247] = Color3.new(199/255, 199/255, 0/255),
    [248] = Color3.new(0/255, 128/255, 0/255),
    [249] = Color3.new(0/255, 100/255, 0/255),
    [250] = Color3.new(0/255, 0/255, 255/255),
    [251] = Color3.new(0/255, 255/255, 255/255),
    [252] = Color3.new(220/255, 220/255, 220/255),
    [253] = Color3.new(169/255, 169/255, 169/255),
    [254] = Color3.new(255/255, 145/255, 0/255),
    [255] = Color3.new(222/255, 0/255, 255/255)
}

game.Players.PlayerAdded:connect(function(plr)
plr.CharacterAdded:connect(function()
    local rank = plr:GetRankInGroup(1214054)
    local role = plr:GetRoleInGroup(1214054)
    if rank ~= 0 then
        local rankd = game.ServerStorage.Rank:Clone()
        repeat wait() until plr.Character
        rankd.Parent = plr.Character.Head
        rankd.TextLabel.Text = role
        rankd.TextLabel.TextColor3 = ranks[rank]
    end
end)
end)