I get your point, but in Chicago cabs do not have to be painted yellow in the first place. In fact, outside of yellow cab, very few are.
I do agree that some form of better markings are called for, and Uber and Lyft drivers could put small but noticeable signs on the roof (like Pizza delivery drivers use to do) with a pretty minimal burden. The rub is a lot of the drivers have both apps running at once, but that's still something signage could deal with.
If all TNPs are regulated by the city to the extent of drivers being registered with the Department of Business Affairs and Consumer Protection (I'm not sure whether or not they are), you may be able to report bad driving on BACP's web site, as you would for reporting a cab driver.
Yes, you can file a complaint through 311 (I recommend using the phone app — it’s the easiest way to file), and the complaint will be reviewed and adjudicated by BACP. I’ve successfully gotten a few Uber/Lyft drivers fined for violations.
Really?! Do you just need the plate # to file a complaint?