Why does the FogColor not change?

I'm trying to make a script that changes the FogColor of Lighting when the ClockTime changes, however it produces no errors in the output.

local lighting = game:GetService("Lighting")

lighting.Changed:Connect(function()
	if lighting.ClockTime == 6.4 then
		for i = 1, lighting.FogColor.R do
			lighting.FogColor = lighting.FogColor + Color3.fromRGB(1, 1, 1)
		end
	elseif lighting.ClockTime == 18 then
		for i = 1, lighting.FogColor.R, -1 do
			lighting.FogColor = lighting.FogColor - Color3.fromRGB(1, 1, 1)
		end
	end
end)

Why isn't this working and how can I fix it? Please help!

it should work.

if it doesnt work than it is the RGB coloring part or that everytime a lighting property changes the if statement will run again so depending on how long you make each day in the game the fog lighting will only change when clocktime is at 6.4 and 18