Is it possible to dynamically size a shape or image during a report run - without the complexity of building a custom report listener?

I'm looking for a way to visually illustrate percentages via a horizontal colored image or shape scaled to a specific width.

Ideally what I would like to do is dynamically size the width and color of a shape.

Is there a simple way to do this or is this just the type of feature tailor made for a report listener?

Thanks,

Malcolm