iMessage: Gray recipient list

I recently did a "Reset All Settings" on my iPhone 6 to troubleshoot an issue. After that, I noticed that iMessage on my iMac had changed.

Normally, the column on the left highlights the active recipient in blue. After I did the reset on my phone, they all appear as a dark gray. All my devices are logged in under the same account.

Messages appear to work, and the received bubbles are in blue. It's the gray recipient colour that has me stumped. Does anyone know what this is?

TIA