Short answer: There isn’t a single universal reason; green attire on coaches today is likely tied to ongoing awareness campaigns, special-event uniforms, or team-specific promotions happening this week. To give a precise explanation, more context is needed about which league, team, or event you’re referring to. If you can share:

• The sport (e.g., NFL, NCAA basketball, college football, etc.)
• The team or event name
• The exact date and location you saw the green attire

I can pinpoint the exact reason and provide any official statements or context from that event.