As the prophets foretold: The next step was indeed colored pencil tracing!
Here we have the happy color in color - quickly hashed out color, but color nonetheless. I tried a few things in drawing this one, namely tracing using the color of what I was tracing instead of black. Mixed success. The downside to black is that once it smears, it's there forever (see Harvey's foot); the upside is that comics work well with a strong black outline.
Best results might be in attempting to do the outline last instead of first, limiting the smear. That would be rather difficult, but nothing about this project is that easy. Another solution is to simply go with a pen and ink outline. The only downside to this is that ink shows through the card stock, so the card will have to be one-sided or the stock will have to be card-ier. This is why we do mock-ups, people! Things are learned!