User blog comment:ArceusFan2013/October 25th - New Feature: Characters!/@comment-6138112-20131025193734/@comment-6138112-20131027125423

To distinguish it from war-colours (Red, Blue, Yellow and Purple) and from map colours (Cyan, Green, and Black) and speaking (White, Light Grey), We need to have a unique colour. So... Orange? Teal? Maybe Indigo?