Tweak colors of new magic tokens

Summary: Uses shades for token colors, makes function tokens white/blue.

Test Plan:
Used the new tokens in UIExamples, Differential.

{F376191}

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D12465