What catches more fish Color or action ?.
I have a second question if you were to pick one bait which one would you pick.
Lure action by design in combination with lure size are two key lure components I match to fish activity. Sometimes fish will hit a 5" plastic worm, at other times 1.5" plastics. Along with design and size considerations is presentation. Wrong presentation and no or fewer fish.

Color can serve to emphasize lure shape and action depending on water clarity, time of day and available light. Black is my least favorite color based on personal bias not proof. As with all the above, confidence in a lure design in certain colors must be considered.

Example:
I have the least confidence in curl tail grubs, but added to a Beetle Spin have great confidence the combo catches fish - and has - all in the same area !


In in the above example flash is added to the combination of lure factors, color IMO is secondary to the combination of lure action, size and the flash of a small blade.

As far as a personal favorite - for me there can never be just one. The more the better on a daily basis - some far more versatile than others.