From http://www.ananova.com: ‘ A blind woman has baffled scientists after proving on TV that she can distinguish between colours by touch. Gabriele Simon, 48, from Wallenhorst in Germany, revealed her ability in her country’s most popular TV show Wetten dass. She used her fingertips to recognise the different colours of various t-shirts and blouses while blindfolded. She said: "I took me 20 years to master this skill. It is a combination of pure learning and concentration." ‘
I would not be surprised if the "test" used her own clothes and different color clothes have different tactile properties.