Mu paints its equipment in stardard Adder black and dark blue with blue and green highlights.
Per FM:Crusader Clans, page 128.
All Adder ‘Mechs and fighters bear the Clan insignia on the left arm or wing and right leg or empennage. Galaxy insignias are displayed on the right arms or wings and left legs or empennages, while Cluster insignias are worn on the right torsos of ‘Mechs or the fuselages of fighters.
The Greek letter Mu emblazoned on the Star Adder emblem serves as the Galaxy’s insignia.
Per FM:Crusader Clans, pages 118 and 128.