game.Workspace.Part.BrickColor = BrickColor.new("Really Blue") end
Like so?
BrickColors are case sensitive! All capitolization must be exact.
Your problem was that you put "Really Blue" as the arguments for the BrickColor.new
function - when you should be putting "Really blue".
Also, there's no need for that end.
game.Workspace.Part.BrickColor = BrickColor.new("Really blue")