The REM sleep, rapid eye movement, dream state, is in light green; and light is gray, light sleep; and deep sleep, the best restorative sleep, is that dark green.
当你处于快速眼动睡眠（REM=rapid eye movement sleep睡眠中眼睛迅速转动） 状态时，显示为绿色 当你处于轻度睡眠状态时，显示为灰色 当你处于深度睡眠状态时 呈现的是深绿色