Digital Workshop

I have an old publication that I produced some years ago in which I used 'Change Polygon Fill Colour' for the user to recolour different parts of an outline image. It worked quite well at the time. I am now creating a publication which will be exported as Opus Flex. I was wondering if there is a different way to reproduce the 'Change Polygon Fill Colour' effect since this action is not available when using the Flex format. Any ideas?

Using Opus Pro 9.03 / Windows 7