Brothers from the same mother?

There's white stuff laying in the ground outside this morning (it was snowing heavily through the night) and so I've fed the birds, turned up the heating and I'm spending the rest of the day in the warm.
These polyanthus are some of the plants in the large glazed pot that were given to me for my birthday and to all intents and purposes there appear to be two totally different coloured flowers from the same parent plant. Is that even possible? I've looked very closely and I can't see anyway that it's two plants that have just been planted very close together... is this just a throw back of nature? Can these two possibly be from the same mother plant?