How can I change the color of block when the tool is not in use?

I have a block that changes color and text when it the tool is in use. It doesn't work, even though the tool has its bool value changed to true. Anyone know how to fix this?

InUse = game.ServerStorage.Key1.InUse.Value
while true do
	if InUse == true then
		script.Parent.BrickColor = BrickColor.new("Really red")
		script.Parent.SurfaceGui.TextLabel.Text = "Key1: In Use"
		wait(1)
	elseif InUse == false then
			script.Parent.BrickColor = BrickColor.new("Bright green")
			script.Parent.SurfaceGui.TextLabel.Text = "Key1: Not In Use"
			wait(1)
	end
end

Mostly issues occur from efficiency problems, in this case, this is probably what's causing your problem. @theking is right, tools have an equipped and unequipped event. It's best to use these to your advantage. For example...

local tool = --//Index your tool
local handle = --// index handle
local gui = --//Index GUI
local colors = {"Really red", "Bright green"} --//Optional

handle.BrickColor = BrickColor.new(colors[1]) --//Assuming 'handle' is the object being colored

tool.Equipped:Connect(function()
    handle.BrickColor = BrickColor.new(colors[2])
    gui:WaitForChild("TextLabel").Text = "Key1: In Use" --// Efficiency tip: Sometimes the script can run faster than the asset can load, so we yield it until it exists, this should be used to index most things.
end)

tool.Unequipped:Connect(function()
    handle.BrickColor = BrickColor.new(colors[1])
    gui:WaitForChild("TextLabel").Text = "Key1: Not In Use"
end)

Hope this fixes your problem