db4tch:

I changed the sky colour to a deep pink, but the picture remains the same. Therefore, the blue must come from somewhere else, as I already suspected. Time is set as 02:14 AM, so I would expect the sky to be black(ish).

I changed the ground colour to a vivid pink, as you can see just in front of the yellow wall. The black band above the wall is the dark ground.

Note: in the render settings all lights are turned ON.

Hans