Silver, Grey, White, Black, Blue, Red, Green, Beige.
Not really sure what you guys are looking for.....? Those are pretty much the standard colors that the large majority of cars are sold in.
Occasionally you'll get something wacky like a lime green or a sunburst yellow offered on a car.... but these are flagship Mercedes 4x4's, not Mazda Miata's. I don't know for sure but I don't believe Escalade's come in bright yellow, and I don't think Range Rover's come in dayglow orange. Then again, maybe they do.
And of course, if you're going to spend $100,000 on a brand new G, I'm sure you can flex your financial muscle and get it delivered in whichever color your wife desires. But if you're buying a 10 year old one, and looking for that holy grail of lower mileage, excellent condition and extensive maintenance history, as well as 100% stock, you aren't going to be able to be that picky. They didn't sell a ton of these things, to begin with.
As for spray-on plastic... if you're going to spend $30-40k on a G500, it's gonna take some balls to rattlecan it. Better you than me.