The radio uses about 50% of the battery capacity when the prop is “sleeping” for approximately a month. The prop automatically turns off the radio after 1 month of sleep. When your props are running, the radio uses more power than when they're sleeping, but power usage is insignificant compared to the LEDs. 

If you want your props in low brightness to run for multiple days straight, then yes, setting the grouping to red would help. Otherwise it’s insignificant.