Tau gun drone

Few days ago my order from Maelstorm games arrived. I got box of firewarriors and Devilfish transport vessel. I decided colors of my army would include black and green at least. So i grabbed my only brush and started painting. This gun drone is my carrying my test color scheme. Only few colors in it, mainly chaos black and scorpion green. Lenses are painted with warlock purple and metal bits in gunmetal. Everything is washed with asurmen blue.

First test Tau

As JasoX pointed out, im drilling gun barrels later when im going to get a drill first

Im thinking of adding some kind of symbol at the top

 Firewarriors in backround

Looks pretty nice from my point of view. Before this gun drone i have only painted few random space marines and few orks, the ones from Assault on Black reach have. Hoping to get full squad of firewarriors painted soon, any ideas how to arm them? Pulse rifles or Pulse carbines? Combination?