Where can I find sources showing ecclesiastical vestments of the 1200s?

In 1215 at Runneymeade, barons and clerics gathered to get King John to set his seal to the Barons' Charter. According to Roger of Wendover , among them were the pope's representative, Master (bishop) Pandulph , 2 archbishops, 10 bishops and 20 abbots. What colours would the different ranks of clerics mentioned have worn at this period? If anyone could point me to a reliable source on historical vestment colours according to rank, rather than seasonal liturgical use, I'd be most grateful. ADDITION I'm grateful for the responses, and have meanwhile followed a hunch on sumptuary law. According to Wikipedia , >The earliest sumptuary regulations in Christian Europe were church regulations of clergy, distinguishing what ranks could wear which items of vestments or (to a lesser extent) normal clothes on particular occasions; these were already very detailed by 1200, in early recensions of canon law. Next followed regulations, again flowing from the church (by far the largest bureaucracy in Medieval Europe), attempting to enforce the wearing of distinctive clothing or badges so that members of various groups could be readily identified, as branded criminals already could be.[citation needed] This seems a possible source, but I don't read Latin fluently. I found it via this link. If anyone can help further, I'd be grateful.