So I just remembered that there is some sort of small waterfall in the ROTR queue. I think they were going for a pretty stark contrast between the ROTR and First Order side of the land. The ROTR queue and surrounding area has a waterfall, caves and trees- things we that come to expect at Disneyland that are pleasant and/ or mysterious. Probably to evoke hope- which is what they want you to feel on the Resistance side of the land. The other reason is they are trying to enforce that there is some space between the two areas.
The First Order side/ village is mostly a dreary sea of beige and things that are broken, blasted etc.. With that said, From what I’ve expeienced, I don’t find the contrast very obvious as the trees/ landscaping is more dessert chaparral not Forresty, the waterfall can only be seen in the queue and beige/ tan still dominate.