I do not care for the colt guns prior to the python. The python and similar, latter detective specials and the magnum carry are very attractive to my eyes.
Early i.e. 30's / 40's DA guns I really have always thought the Smiths looked better than the Colts.
If I had to rationalize it I would say I find the frame of the colt less attractive than the smith, putting some nicer details on it and the nicer barrel as on the python makes it look better. From a shooters perspective I still think the 686-4 is about as good as it gets looks wise, and shooting wise.