Several people have been discussing these lately, for obvious reasons. See the following thread. The use case there is for something to indicate that the security system is armed, but it’s very similar:
By far the easiest is probably to get a plug-in LED strip, and that way you can change it to different colors for different notifications. So red for “don’t come in I’m on a conference call,” yellow for “I’m working, but come in if you really need me“, etc. 
The Sylvania strip works directly with smartthings. The hue strip should be used with a Hue bridge.
Either of those will be easy to set up and use and also work well with voice assistants.