improve Rainbow Mode

 * Require 5 consecutive menu "wraps" in the same direction to help
   prevent accidental toggling

 * Align colors into stripes (i.e. columns)
   a) less prone to induce dizziness in some people when they change
   b) better resembles a rainbow

 * Move the stripes to the right when the selection moves up and
   move the stripes to the left when the selection moves down

Change-Id: I3feae173b22f5703c554ca33e634881749ff54cf