I use rubber legs on alot of flies. Usually solid colors as tha tis what I have in abundance.
I tend to use thicker rubber for the flies. I fidn that the small and extra small tends to hold to the side of the flies. One the rubber touches the side of the fly the water cohesion is to strong for the rubber to break.
That is why I go thicker rubber and shorter legs than are found on most commercial flies.

Rick