PHUITagColors for Objects

Summary: Provides a base set of shaded object tags for use in Phabricator.

Test Plan:
Lots of Photoshop and Chrome.

{F170252, size=full}

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D9737