he has a double lightsaber

xenadd‘s concept art for Kanan’s Inquisitor uniform in On the Edge of the Devil’s Backbone.

Kanan’s uniform has the signature Jedi tabards and belt (the Inquisition doesn’t want him to forget where he came from or what he gave up), with Caleb and Depa’s arm wrappings from Kanan - The Last Padawan and Kanan’s boots  from the show, but in heavier Imperial fabrics, with a Vader-y silhouette and armor that mimics both Anakin and Obi-Wan’s from TCW S1-2 and the Inquisitor’s in Rebels S1.  In color it would be black, with maybe a very dark red underlayer.  Both pauldrons have the Imperial cog painted on.

Kanan’s doesn’t have the round-pommeled double-bladed lightsaber of the show Inquisitors; he has a single-bladed red lightsaber with a black hilt whose final design I haven’t done yet.