the out come of mixing brown and orange is a lighter brownish colour. (A&W style)
if you mix blue and yellow you get brown not orange to get orange you mix red and yellow
orange and black
It would make a different shade of brown. Orange + Green = Brown
Brown
ORANGE
brown
Brown.
Depending on how much brown you add you will get anything from a deep orange to a rusty brown.
I think you are mistaking the orange color for brown. The orange do really look like brown on normal capes. Anyways, mix red dye with yellow dye for orange dye. When you use the orange dye on a normal cape, you will get your " brown" cape.
Brown - chestnut perhaps, if your orange is blood orange (a red orange)
brown
Dave