[marze]

I use orange led bulbs in a parallel system to the white lights. Some in lamps plugged into a power strip with a switch.

Simple and cheap, but requires extra lamps.

[scarby2]

The cost of a lamp a tunable bulb and a fraction of an rpi is almost certainly lower than the cost of 2 lamps and 2 bulbs.

[marze]

Two things, I set this up long ago before tunable bulbs were cheap, and the single tunable bulb I checked out subsequently didn't emit just orange, it had some blue.