Okay, it makes sense that they are colours on the cave wall, I'll grant you that point. Even so, there's no reason why the colours would run uphill. They would still run horizontally in the background even when the ground slopes.
In #524 there are people on 2 levels of the cave, there's probably a slope to get from the lower to the higher. The bands of colour in the cave would still run horizontally behind the slope, right?
How does that work? If something is running along the floor, does it disappear when the floor starts to slope up?