This is a modified piece of work. The base image is taken from concept art for the new Mechwarrior Online game: what I did was apply a new paint scheme to the Battlemech changing it from a Federated Suns Centurion to one form the 13th Marik Militia. I had a lot of fun with modifying this. I'm really hoping the game will allow this level of texture editing :d
Credit to Piranha Games for the original concept work.
Credit to flyingdebris for the original art.