Basing my Astral Knights

I'm trying to find a basing theme for my astral knights that fits with the fluff but also works with the color scheme that they have.  So far I have just painted the bases a tan colour as it was the nearest thing I had to hand.  It turned out the colour looked really good, the warmth of the tan really made the cool blue, white and silver of the models stand out.  Now I just need to tweak it to fit the fluff and look more realistic.

I found this lovely tan coloured base on from the warp, which I think has the right degree of subtle texture and variation without being too distracting.

A rather happy coincidence was that they are bases for necron models, now the limited fluff we have about the Astral Knights mentions their destruction at the hands of necron force.  So why not use this to theme my bases?  I could use bits of necron warriors and scarabs to litter my bases with their fallen foes, The fact that they can be painted metal and then washed to make them look part of the base is just a bonus.