Don Sebastian appears in only two episodes of the fourth season plus some flashback shots in "New Lion of Sonora".  This muted blue suit with the dark collar appears again in all three of these fourth season episodes, and is probably his most frequently seen outfit of the series.

Two new outfits appear for the first time in the fourth season.  One is brown with orange filigree stitching on the lapel trim.  The other is grey with gold line trim on
the lapels and pockets.  Both are working or traveling outfits.