Ah, it says near the end of the book that he has Tan gloves on. We can assume that because he has tan gloves, and that the gloves of a mandalorian soldier match the jumpsuit (for the most part; at least in that era judging by jango fett's armour and the comic book "Open seaons"), that his jumpsuit is a Tan colour as well. I'm not at all sure what the heck his armour colour is, but what would look cool is a metallic copper or maybe gunmetal for his armour plating.