This is SO RANDOM AND FUN! Upfront: no one needs colorful rocks in the desert, it's just not necessary. Honestly, the idea that there's even a yelp review for this is a little silly- "Well, I truly dislike rocks and bright colors hurt my eyes, so in a word- underwhelming."
This is totally just a way to break up your drive to Vegas. It's fun, different, and not even that much of a detour. Plus it's not a permanent installation (to my knowledge), so if you even have an inkling that you'd like to see it, do it now.
All that being said- you can really only drive to this. If you're flying into Vegas, it's gunna be rough trying to coordinate a visit. Also, it is in the desert, so it can get quite windy- to combat sand in your eyes, just wear a large pair of goggles; they'll fight the sand and you'll look super cool in all your photos.