I've had rotundifolia from local (Welsh,) stock produce pink petals
this Spring in a dramatic change from the usual white. I'm still
not sure why, but the extremely intense artificial lighting (at
almost point-blank range,) might have had something to do with it.
Slack (I think it was Slack,) mentions that there are consistently
pink-petalled specimens to be found occasionally in North America,
though I've never seen one before my own 'freaks'.
Happy growing,
Peter