How do I make random colors?

This won't work for some reason:

while script.Parent ~= nil do
	script.Parent.PointLight.Color = Color3.new(script.Parent.PointLight.Color + Vector3.new(math.random(-1,1),math.random(-1,1),math.random(-1,1)))
	wait(0)
end

It says it's getting a userdata for some reason, when it needs a vector 3.