There is no difference in color between the churchills. I use churchills in the winter because they make this biggest XL fins but during the summer I rock tech2's. Personal I like techs a lot better I actually cut the tips off of my churchhills.
I've been using Eon fins for some time now, and I have some Vipers that I can't wear with the booties cause they're not big enough and cause foot cramping.
Another company called Limited Edition (I think) makes Makapuu-like fins in different colors, and they're shaped the same way. A lot of Australian pros have their own signature models of them. I've never taken to Techs cause they seemed too floppy for me, I need a stiff blade. The Makapuus seemed to awkward for me and seems like they require a different stroke.
Fins shouldn't have anything to do with being able to do forwards or reverses. The only difference the stiffness makes is the thrust. * Some companies do market the stiffness and the shape of the fin in a way where people think it gives them an amazingly better hold on the wave to.