IMO, older patterns remain favorites because they've worked well over many years. Folks are therefore reluctant to change. However, that particular fly is of a style that is fairly basic & not unique, so if you were to experiment with colors, you would likely end up with a pattern that is already in use, or close.
Nothing wrong with experimenting, either with various colors or with alternative materials. That's likely how most flies are developed.
I recall a story about the Silver Outcast streamer being the result of an attempt to tie another pattern, and it was tied wrong. The Silver Outcast is still a pretty good pattern. Sometimes mistakes lead us to something productive too.
Sounds like you're new to tying, so following established patterns is a great way to learn the tying techniques & becoming familiar with various materials & their properties. Once you get further into it, you can then do anything you like, and will probably tie some of your own ideas that will work just fine.
Tying is not an exact science, and it's fun to try different things. Otherwise, we would all be tying & fishing a few patterns, which would be boring as heck!
BTW, the Fall Favorite is a darn good Shad fly tied in appropriate sizes & Crappies & Perch like it also!