Help with a Day/Night Cycle

So I made a D/N working system by following this tutorial How To Create A Day And Night Cycle - Unreal Engine 4 Tutorial - YouTube and I noticed that my night sky was still blue and I tried to darken the night sky by adjusting the brightness from the PostProcessVolume, but now midday my sky turns red and stays dark in the night but also in the morning.
I have a video but I can’t upload it.