Why does Color3:lerp() return nil?

for i = 1, 100, .01 do
	wait()
script.Parent.BackgroundColor3 = Color3:lerp(30, 41, 255, 1)
end

Whenever I play the game, it says "attempt to call method 'lerp' (a nil value)"

Help is appreciated, thanks :D

It is returning nil due to the fact you are calling it to Color3. You should call it on it after you construct it with the constructor. If you are using .new you should do r / 255 g / 255 b / 255 since it receives decimal values however with .fromRGB you can use your current values

script.Parent.BackgroundColor3 = script.Parent.BackgroundColor3:lerp(Color3.new(30/255, 41/ 255, 255/255), i / 100) -- I'm pretty sure this is what you want to do

or with .fromRGB

script.Parent.BackgroundColor3 = script.Parent.BackgroundColor3:lerp(Color3.fromRGB(30, 41, 255), i / 100)