I don't think he is wearing particularly opulent garb.
Sigurður jarl hafði brúnaðan kyrtil og rauða skikkju og drepið upp
skautunum, fitskúa á fótum. Hann hafði skjöld og sverð er Bastarður var
kallað.
(Magnus saga erlingssonar, ch 13, quoted from Snerpa.is)
"He had a brown colored shirt and red cloak and (with) the skirt (of the
cloak) tucked up, shoes (skúa) made of "fit" on his feet." He had a shield
and a sword which was called Bastard."
Cleasby Vigfusson give hemingr as a synonym for fit: the skin of the shanks
of a hide. There was a tradition of sealing an adoption by having the
adopted son and nearest heirs put their feet into a shoe made from the right
leg of a three year old ox to seal the adoption.