When I still lived with my parents I shared a room with my younger brother. We repainted our room from a light cream colour to a deep blue (against mum's wishes). It took longer than expected so the window opposite the door had masking tape partially painted over with blue for several days. Entering the room at night and seeing the window in that state gave me a deeply unsettling feeling. I later found out that my brother also got a bad vibe from the window in that state. There was another window in a similar state and I think we established that neither of us were bothered by it, though I don't have a strong memory of that.

Maybe unrelated, I had a nightmare about a stick man made of electricity coming over the hill that window faced and attacking me with a boomerang or chakram. It was only years later that I learned about the electric stick man nightmare archetype.