How to create a brush that contains a full colored pattern

I purchased a brush with each brush containing a full colored pattern (texture). By that I mean that each brush contains the exact print/colors of the pattern.

I love this set  and would like to create brushes like this myself, but cannot figure out how. I thought I could do it in Brush Settings>Texture, but that does not work. (see screen capture). I've also created brushes around various imagery and the brush shape remains, but the pattern becomes grayscale.

I hope someone knows the secret!