colour changes once but then doesnt?

--localscript--
script.Parent.MouseButton1Click:Connect(function()
	if script.Parent.Check.Value == true Then
		game.ReplicatedStorage.Event:FireServer(script.Parent, script.Parent.Check.Value)
	end
end)

--server--
game.ReplicatedStorage.Event.OnServerEvent:Connect(function(player, Button, Check)
	if Check == true then
		Buttoon.BackgroundColo3 = Color3.fromRGB(30,30,30)
	end
end)

it changes the colour first time but it wont after that idk why. the gui is only local.