I won’t be converting the Hank RGBW LED Bulb DTH into an Edge Driver so it will stop working once the Groovy platform is retired, but it probably doesn’t need a custom driver.
This is a device handler for the Hank Z-Wave Plus RGBW LED Light Bulb (HKZW-RGB01)
Tried this on a SmartThings V3 hub - edited the device info to point to this handler after I copied the code, created and published for me - seemed to take the change ok but the bulb would not connect to the mobile app once that was done. The web page shows the correct status of the device. Switched the DTH to RGBW Light and the bulb now connects to the mobile app and seems to work ok but some voice commands via Alexa don’t work (e.g., Table Lamp Red - Table Lamp is the name of the device). This is my first attempt at using this DTH so I am probably missing a step or two 
Any ideas?
It sounds like you’re using the new mobile app, but custom handlers are only supported by the Classic mobile app.
Exactly right - installed the classic app and it all works. Thank you!
I won’t be converting the Hank RGBW LED Bulb DTH into an Edge Driver so it will stop working once the Groovy platform is retired, but it probably doesn’t need a custom driver.