I have a tunable color + white bulb and there is an option to adjust brightness setting. For example if you slide your finger over the bulb (top to down/ down to top) it changes the brightness from 100% to 1% or vice versa.
<img src="//forumus-uploads-production.s3-us-west-2.amazonaws.com/original/3X/6/4/64f872eba6d7bdb62981d15fbc452e886392f644.PNG" width=“281” height="500r