The rule of the Order determined the color of the coat. I be;ieve that if you follow those other orders who followed the Templar rule and those who followed the Hospitaller rul you will find the answer as to the correct color for coat. The Templars and Hospitallers started both with balck but Templars very early in ther history turned to white. Hospitallers keept black until the early 14th c when they changed to red coat with white cross. My doubt is with the style of the cross...yes it is supposed to be ended each arm with a fluer de lis with leaves turned back as if to form a letter M...but how "flourished" was in the Middle Ages Im in doubt...one has 17th C paintings depicting Calatrava and Alcantara Knights and the crosses are "flourishy" but...it was an stylization of late or in medieval times was more simple?Just wondering oit loud...teh painting is excellent Dave..