Here is version 3.0 of my new smartapp: Garden Hue.
I could not find a smartapp that would change the color every so often sunset to sunrise…
So far I have it cycle through about 16 colors, only turns on sunset to sunrise (with an optional offset) and will change color only between these times, OR if you manually turn one or more of the hue lights controlled on.
I have set cycle times of 10 , 15, 30 minutes, 1 hour and 3 hours. so I can use the built in functions of runeveryxxminutes etc. so as not to overload the backend running on fixed times. (check the docs these randomize the time).
I also have a disable/enable option.
There is is also an option for a random one of the 16 colors instead of cycling through them.
I am using the scheduling/cron feature to do this and also schedule turning the hues on at sunset and off at sunrise.