I don't know if you're an Alexa user, but for this use case, where it's just an indicator and not mission critical, I would be tempted to just get a single cheap WiFi bulb that is Alexa compatible.
Use the Virtual Motion Sensor with Switch device to trigger the bulb in an Alexa Routine to the color you want. Yes it's cloud based and prone to unreliability, but for what you're using it for, it just needs to work most of the time.
Otherwise, for inexpensive Zigbee (not very good color, but good enough), the IKEA Tradfri bulbs are just $20
