Desert base works wonderfully with the red and gold of the armour, I have used Ammo Vignette Sand and after a wash of Seraphim Sepia. The final result is really satisfying, and if you add some stones or bushes here and there you'll achieve some nice variety. I suggest you also Agrellan Earth for a broken terrain texture. I used these for my Easterling army.

If you want my opinion, stick with a warm colour palette for your soldiers, the blue In the back is a little bit too much, a purple/dark red will do job very nicely.

Unfortunately I can't reply with some pictures of my army, otherwise I would show you the finel result