Question about cartoon effect

Is it possible using the cartoon effect to create white edges with transparency? I only see how to make black edges with white filler. The project I'm working on is a blueprint graphic. I want to have interview footage start as a still frame (white outlines of the person on the blue paper). As they begin speaking I will blend in the original footage, then as they finish it goes back to white outlines.

Any tips are appreciated.

thx,

Steven