Update the color of FPS text

Change-Id: Ic6f5889e24f98101426fc215c0313122797400b7
Reviewed-on: https://gerrit.libreoffice.org/11507
Reviewed-by: Kohei Yoshida <libreoffice@kohei.us>
Tested-by: Kohei Yoshida <libreoffice@kohei.us>