In Cinema 4D Release 19, the Manual tracking has received a couple of enhancements. The first is the ability for a Manual tracker to see individual colors, rather than only the luminance of the Tracked footage, and enhance the contrast for a specific feature. This eliminates a lack of tracking accuracy with features that have different colors, but similar Luminance.
The second enhancement is the addition of a Circle as an alternative Manual Tracker Shape, alongside the existing Square. This is a User Interface enhancement that allows for better precision when placing Manual trackers on Spherical Features.