How do i get my text GUI to update properly?

I checked through the website and all of the results i wanted didnt help fix my issue so i am now asking for help. I am having an issue with a gui changing script where the printing works properly but hte GUI doesnt update at all. the code is:

--instances
local Player = game:GetService("Players").LocalPlayer
local Text = script.Parent.Text
local Color = script.Parent.TextColor
local Textchange = script.Parent.TextChange
--functions
local function SetText(Ammo, Ammocap)
    print(Ammo.."/"..Ammocap)
    print("before if argument")
    if Ammo / Ammocap < 1.5 then
        Color = Color3.new(0.807843, 0, 0)
        print("in if argument")
    end
    print("after if argument")
    Text = Ammo.."/"..Ammocap
end

--function connects
Textchange.Event:Connect(function(Ammo, Ammocap)
    print("triggered Bindable Event")
    SetText(Ammo, Ammocap)
end)

alos i am certain that all of my instances are correct, hte text just doesnt update correctly