Find someone running a CheerLights and then ask Alexa to change the colour. This skill will send a tweet to Twitter changing the colour to that requested. The tweets appear under the Twitter account https://twitter.com/EchoCheerlights
You need a CheerLights device, for details how to build one see:
Alternatively you can install one of the CheerLights apps:
- "Alexa Ask Cheer lights to turn green"