OBS is going to be very limited with what you're looking to do. Chroma Keying is about as advanced as it gets for the filters you can apply... but no type of extra image recognition is really possible (a la 10 yard line processing, which requires dedicated production-level processing to handle in realtime).
Something that you could do if you're looking to remove only the lines is to do a selective area key (this will only work if the camera is 100% fixed in place, and the lighting is consistent).
Basically, you take your static frame, pull it into photoshop, and paint out the lines you don't want shown. This will be your clean plate.
Then, for every color of line you want to remove, create a layer mask (white area for the line area, black for everything else). In OBS, create a new scene that just contains your camera -- add a chroma key filter to this which keys out the intended color. In your original scene, add a group with your clean plate on bottom and your new scene on top. On that group, add a image mask filter with your color's mask (the black/white image).
That should effectively paint in fake background to every area that matches the colored lines, and it minimizes the overall times that it will interfere with jersey color matching (the only time it would happen then would be if a jersey is actually the same color and on top of the line directly).
It's not perfect, but without extra processing, that's about as good as it gets.