Oca Variety Roundup.

It had to be done! I've assembled a spectrum of Oca varieties from various sources, and am cataloging them here.  It's quite odd that there are no accepted named varieties of Oca in Europe or North America, or at least none that I know of. Feel free to correct me on that.
I'm cataloging them simply by background tuber colour, and eye colour. I will add any other characteristics or identifiers once I see the plants growing, along with any observations on their habit or productivity.

Pale creme, self-coloured eyes (aka 'White').

Pale creme, pink eyes (possible variation on right, pale creme, purple eyes)

Pale yellow/green, self-coloured eyes. The colour difference between this and 'pale creme' is not very obvious on-screen.

Pale gold, purple eyes.

Pale pink, purple eyes.

Rose, self-coloured eyes.

Pale red, white eyes. Source, a sport of Real Seeds 'Red'

Scarlet, white eyes (aka Real Seeds 'Red')

Dark scarlet, self-coloured eyes.

Orange-pink, purple eyes. Offspring of tubers bought in a UK supermarket eight years ago, so almost certainly a New Zealand commercial variety. Thanks to Catstripe for the tubers.

Ruby red, white eyes. Again, from tubers bought in a UK supermarket eight years ago, so almost certainly a New Zealand commercial variety. Again, from Catstripe.

Many of the varieties above are courtesy of tris0070 who provides Oca and other unusual tubers via eBay.