while true do wait() if script.Parent.Parent.Parent.Parent.TeamColor == "Brown" then script.Parent.Image = "http://www.roblox.com/asset/?id=141566394" wait(15) end end
The parent of this script is an image label, whose parent is a ScreenGUI, whose parent is StarterGUI.
Okay so this might be the problem, not entirely sure but firstly with colors in scripts you have to put (in this case, BrickColor.new but there's also several other ones) BrickColor.new("Color name here"). Secondly, with images, they have to follow the proper format. The link is rbxassetid://(ID number minus 1).
--For the color part, you would put TeamColor == BrickColor.new("Brown") then script.Parent.Image = "rbxassetid://141566393"
More details on BrickColor here