Herald - make flag color display

Summary: It used to say "Mark with flag 7" or whatever, and now it says "Mark with flag Checkered"

Test Plan: noted previous rule I made was more understandable

Reviewers: epriestley

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D8158