Q.Pomegranates look burned
I live in Las Vegas where it can get pretty sunny. What could cause my pomegranates to look so off color? Instead of a shiny ruby red skin, I see decidedly duller colors. Some of the ones in the middle of the tree where fruit gets most shade are still white with little red. I do throw coffee grounds and eggshells in the surrounding soil frequently.

I do think that your Pomegranates are suffering from sun scald. Fruit that grows on the outside of the tree would be more susceptible.
The combination of the sun and the white reflecting from your house is likely the cause.
You can try adding some shading to the plant.
Here are some links for you with more information.
https://www.gardeningknowhow.com/plant-problems/environmental/sunscald-on-plants.htm
https://www.gardeningknowhow.com/edible/fruits/pomegranate/diseases-in-pomegranate.htm