Few dyes from plant xources are satisfactory.The royal purple of antiquity was derived from marine Murex snails, and so expensive only royalty could afford it, and it was forbidden to anyone else. Not until Perkin's discovery of dyes from coal tar could average people have pretty colored clothing.
T shirts colored purple from fruit will fade and just look messy. Only valuable plant color I can think of is indigo, first available in 1745.