> I think I was doing myself a disservice

Were you able to run a data comparison in terms of users/time on site/number of pages etc. I would assume that this in itself would clearly tell you if the ads were harmful or not.

> I don't see how font styles and colors affect the cost of the website

What I mean by this is that when you visit a site with these native ads, the ads themselves would have to adhere to strict design requirements laid out by the publisher. The idea being that it is less intrusive for the overall UX which in reality should limit the problems you mentioned in terms of 'quality'.

The neon, 90's style banner ads are very off putting when you browsing a site, which is what the above is trying to combat.