How can I change the colors of armor parts in a player using a GUI?

I'm trying to change the color of armor with specific names using a GUI. The problem is that when I click the part, it shows an error saying "attempt to index local 'player' (a nil value)".

script.Parent.MouseButton1Click:Connect(function(player)
	local target="PrimaryColor"
	local char = player.Character
	for _,p in ipairs(char:GetDescendants()) do
		if p.Name=="Primary" then
			p.Color=script.Parent.Parent.Frame.Picker.Colour.BackgroundColor3
		end
		end
end)

This is what the armor looks like.

Here is the GUI, for context.

If I recall correctly, you can't use LocalScripts to change block's properties. You'd have to use events instead.

Not sure if this is the cause of the error, but maybe something you could try.