Base coat; there are three or four thin coats of Vallejo dark sand, cunningly modulated over a several week nights (Mrs Z suddenly found a social life !) and finished with a top coat of Tamiya dark sand (actually a lighter colour). The (what-would-ABS-or-fibreglass-IRL) radar covers are Tamiya black-green over a coat of Dark Angle Green.
Decals next ! Oh and, acrylic butile styrene, in case you were wondering, like a motorcycle fairing.
And as mentioned in the comments here is a pict from Ratguard showing the active radar array from under the cover: For more picts follow the link.