The Thirteenth Sun Zhang adopted an off-white paint scheme with blue striping so dark it looks black in dim light.
Per FM:Draconis Combine, page 91.
Every ‘Mech carries the House Kurita crest on its upper left torso. The Sun Zhang Cadres insignia, a setting sun, appears in a different location depending on the cadre. The Fifth Cadre has its own regimental insignia, though any cadre ‘Mech may carry a banner with the cadre name on it. Every unit BattleMech carries the banner of the Thirteenth Cadre, and the Thirteenth’s aerospace fighters bear a facsimile of the banner on their fuselage. The Sun Zhang Cadre insignia appears on every BattleMech’s upper right arm. Per FM: Draconis Combine, pages 89 and 91.