- Reset _npc_entity_colors/_npc_entity_id/_next_npc_color in _end_player_conversation() to prevent palette exhaustion across long sessions with many unique NPCs - Re-enforce contrast floor after passive desaturation (_enforce_contrast after _desaturate) - Add TestDialogueSpeakerColors suite: palette allocation, entity reuse, reset, fallback Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>