Sorry its got me a bit stumped..

It's outside my skillset, but maybe someone could develop a VBA control assigned to a scroll bar. Then the colours can move based on where the scrollbar is positioned?

Sounds complicated to develop though and not sure it would work within a table though.

Maybe the alternative is to place a number box where the user can place a rating? Again to visually represent it would require some VBA, so you might need to post or move this post to that forum? (the VBA geniuses probably dont come in here much)