I have three planter boxes with pansies in them. I only actually planted pansies in one of them, in the spring of 2015. Since then, I have gotten a wondrous variety of pansy volunteers self-seeding into the two adjacent planters.
The ones I originally planted looked most like the three in the top row. The lavender and yellow were relatively small varieties, about an inch across, and the dark-centered blue was a standard size, about two inches across. Just normal pansies from the clearance rack.
All the rest are spontaneous hybrids that have occurred over the past two years, including that one enormous blue-purple that is nearly as big as the palm of my hand. Such an amazing thing, gene recombination.
This is the original pansy box with stargazer lilies,
this is the other lily planter with volunteer pansies, all shades of lavender in this one,
and this is the curly willow pot, with Doone Valley thyme that is creeping beautifully and a few tiny pink and blue pansies.