This is Confetti Purple Pizzazz and Sinful Colors Purple Diamond:
already talked about). Pizzazz is the one above Convergence & Diamond is the one below. They do seem to roughly correspond to what you see in the bottle, in the sense that Purple Pizzazz reads more pink (or possibly mauve) and Purple Diamond reads more purple. But honestly I'm not sure most people would look at either one of these on the nail and call them purple. This is the kind of thing that I use (when I remember to use them at all) primarily for layering, because on their own, they are barely noticeable. If you like very sheer polishes, these are pretty ones, full of shimmer. If you have the kind of job where many dark or bright polishes are considered beyond the pale, this may be the kind of thing that you may be able to wear. Luckily I don't have that sort of job any more. (Far from being a disadvantage, there are people in my workplace who check regularly to see what crazy color I'm going to put on my nails next!)
Re availability: Confetti used to be CVS' version of Sinful Colors, wasn't it? and they don't carry it any more, to my knowledge. I don't know whether it's available somewhere else or not. And I don't see Purple Diamond on Sinful Colors' current list, either.
Reswatched pictures of Purple Diamond here.
Other people's swatches:
Swatches of P.Diamond over various colors
Swatches of P.Pizzazz (where they agree with me that it should not have purple in its name, but pink)