WebUI: fix the primary/secondary text color

Bug: 849857
Cq-Include-Trybots: luci.chromium.try:closure_compilation
Change-Id: I9a3cbdede42367d8295aacffda69d3965379e942
Reviewed-on: https://chromium-review.googlesource.com/1121336
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Reviewed-by: Scott Chen <scottchen@chromium.org>
Commit-Queue: Esmael El-Moslimany <aee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#572043}
26 files changed