The menaphite purple robe is a type of robe bottom which is a part of the Menaphite clothing used by Menaphites. It can be obtained after completing the miniquest Rogue Trader. Menaphite clothing work exactly like the Desert clothing and Desert outfit, protecting players from the desert heat.
There are two colours for Menaphite clothing: one looks exactly like what the Menaphites wear in Pollnivneach, in that these are purple and yellow. The other set is in red and yellow, similar to the clothing worn by the people in Sophanem.
After completing the Rogue Trader miniquest, players can buy both of these from Ali Morrisane or switch them out for the Desert outfit. To do the part of the miniquest to earn these, players must have completed the quest Icthlarin's Little Helper.