Tuesday’s guidance includes a color-coded chart that shows activities that fully vaccinated and unvaccinated people can do indoors and outdoors, and which ones can be done without masks. The safest activities, highlighted in green, are outdoors in small gatherings. Activities with the greatest risk are indoor settings that involve behaviors such as singing, shouting, heavy breathing, inability to wear a mask or inability to maintain physical distancing, such as indoor high-intensity exercise class.