Normalize AuditStatusConstant Colors

Summary: Ref T6345, This adds more consistent color choices to match how Phabricator generally works across Differential/Diffusion per user statuses.

Test Plan: Review a few Audits in my sandbox.

Reviewers: epriestley, btrahan

Reviewed By: btrahan

Subscribers: Korvin, epriestley

Maniphest Tasks: T6345

Differential Revision: https://secure.phabricator.com/D10726