Moist bottom or sunkissed top

This LEGO castle by lego_monkey_ is here as a reminder to all that LEGO castles can be colourful and still look amazing. The tower of this creation starts bluish dark grey, gradually fades to sand blue to end up light bluish grey on top. The ombre effect makes me question what is going on with the building. Did the bricks on top of the tower fade due to higher exposure to sunlight? Is the soil on which this tower was built very moist and are the porous bricks at the bottom of the tower soaking up the moisture? I love the addition of the bright blue colours for the rooftop. It matches the bluish tints used for the tower itself but the contrast in brightness really ups this creation. Using orange, which is the complementary colour of blue, as a backdrop is aesthetically pleasing and therefore a really smart choice.