How do I make a block turn white at night and black at day?

I have a text mesh in my game that's outside on the water, and what I've noticed is that you can't see the black color when it's night, but you can see the white color when it's night. Here's what I have with my script so far, but yet again, it's probably wrong. If anyone could make a thing that when it's day - make the block black and when it's night - make the block white. Thanks!

My faulty code:

script.Parent.Name = "LightPart"
lightPart = game.Workspace.LightPart
minutesAfterMidnight = 0
 
while true do
	minutesAfterMidnight = minutesAfterMidnight + 10
	game.Lighting:SetMinutesAfterMidnight(minutesAfterMidnight)
	wait(0.1)
 
	if game.Lighting:GetMinutesAfterMidnight() == 6 * 60 then		-- checks for 6AM
lightPart.BrickColor = BrickColor.new(Color3.new(1, 1, 1))
		lightPart.PointLight.Enabled = false
	end
	if game.Lighting:GetMinutesAfterMidnight() == 18 * 60 then		-- checks for 6PM
lightPart.BrickColor = BrickColor.new(Color3.new(255, 255, 255))
		lightPart.PointLight.Enabled = true
	end
end