All my plants turned purple due to the cold nights, though i did grow some seeds called Purps this year, the difference was that the Purps leaves were a light purple naturally before the cold set in and the other plants that turned from the cold were way dark purple with purple bases on the tricholms. the Purps tricholms heads were purple. So...no matter what i grew, northern lights, old gangster, 420, bubble gum, they all turned purple. But, the Purps were natural light purple leaves, even before budding.
Just my two cents,
inbud