Update Pholio to use pink instead of indigo

Summary: We recently shipping a more color correct version of Indigo, which means Pholio should use Pink for highlights.

Test Plan: Review Pholio Comments, Hovers.

Reviewers: epriestley, btrahan

Reviewed By: btrahan

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D10732