The problem with your code is on line 9 where you attempted to create an Invalid Instance 'Head'.
Head isn't a valid instance type
But alternatively, instead of coloring each limb individually why don't you use a loop to iterate through all the children of the player's character.. then changing any parts(potential limbs)'s colors to the specified color?
01 | local plr = game.Players.LocalPlayer |
02 | local color = BrickColor.new( 'Pastel brown' ) |
04 | script.Parent.MouseButton 1 Down:connect( function () |
06 | for i,v in pairs (plr.Character:GetChildren()) do |
07 | if v:IsA( 'BasePart' ) then v.BrickColor = color end |