Remove some more GrColor references

Bug: skia:
Change-Id: I395395b1cd81a1d45ca779b2273015c8ed9fb882
Reviewed-on: https://skia-review.googlesource.com/c/168361
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
6 files changed