I have the same problem and have tried:
* Making a new profile
* Making one or more static color profiles
* Persist to device, nothing happens, reverts to the frenetic rainbow pattern as soon as I close iCUE.
* Soft reset
* Firmware update
*Repeat all of the above several times
And still, nothing happens. Rainbow madness as soon as iCUE is closed. Judging from how many people have this issue, a fix or guide (beyond the tips available) is sorely needed.