R1:23b2653f52cd

More ActionPanel colors, hardening

Summary: Adds full ROYGBIVP color spectrum, adds basic overflow, collapse protection.

Test Plan: Review small and large panels are various breakpoints.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D14120