After reading this three upsetting things became more apparent:
1) Giger definitely did not design the sculpted mural, it was merely a homage.
2) Ridley was heavily involved in the creature design and he toned down the giger elements throughout the sets and creatures to make it feel "more real" in his words. (SPOILER: I wonder if that is why the pseudo-proto-xeno has pink gums and enamel teeth?: END SPOILER)
3) Carlos Huante (whom is a great designer but not right for this project in my personal opinion) created designs for proto facehuggers and xenos (it sounds like legitimate xeno precursors) and they got cut.
I just can't wrap my head around why Ridley so clearly and specifcially white washed the giger out of this movie. The only exception is the general look of the pilot room and the engineer outer armor. So sad.