Sandy Ussia a contributing PowerApps community expert offers this fun video on how to use the Rand() function to create an app that changes colors when the baby taps on the screen! WOW!
The blog post she did is here:
https://sandyu.com/2017/12/05/powerapps-babycolors/
https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DdmLHmFta_JE