Here in Arizona Pebbletech is the older style of pebble finish that is a bit rougher than smooth plaster. Pebblesheen uses smaller pebbles that is a smoother finish. Pebblesheen is what we will be using in our pool when I get to the interior finish stage. We wanted some texture to the pool finish (and hear that it lasts longer than just white plaster). As far as color, thats going to be a personal decision on your part. For my family we started with what we didnt want. We didnt want a dark lagoon looking pool nor one that looked green. So that ruled out the very dark almost black color and any colors that had green in them. We like a medium but sparkling blue color. The interior subs use different products to telling you a color name wouldnt help you as the names are different.
I have standard Caribbean PebbleTec. It's fine and no one in my family of four kids is bothered at all by the rougher texture. PebbleSheen is certainly nice. When the time comes to resurface, and assuming I'm still here, my hope is that AquaBright will become a little more widely available (and cheaper). It's a flame-sprayed polymeric coating that goes over standard plaster and makes the surface chemically inert. It's tough, durable and UV resistant and it comes in some incredible colors.
A word of caution with plaster colors. All plasters fade in chlorinated swimming pools; there is simply no way to avoid it. You want to use a plaster color that does not use organic dyes to create the color as those are the worst in terms of color-fastness. You will often see dark colors fade very quickly. This is what a Caribbean Blue P-tech looks like -
Notice how the surface color is a dull grey-blue while the bulk plaster color is the expected Caribbean Blue. This is what you can expect from the majority of plaster colors and it happens within the first few years. So you want to be really careful to avoid colors that fade easily and those would mostly be the darker blue colors and darker grey colors.
Wife thought pebble tec was too rough, so we went with the sheen. Really happy with it. Choosing a color can be overwhelming -- I'd recommend going to the website and looking at all the possible variations, really helped us.