That's not all...
')' expected at line 4
The while true do is the priority making it so it would keep running that block... in other words it changes the color of one part.
Neither of your scripts properly gets a random BrickColor. Technically, this would work tho:
children[1].BrickColor = BrickColor.new(math.random(0,255)/255,math.random(0,255)/255,math.random(0,255)/255) |