The cloak in this outfit has a beautiful moon and several hues of blue as base colours. When I picked it I knew I wanted to use it in a moon-ritual outfit, but it was not so easy to combine it with the right complementary colours. In the end I settled on rust as I like how it gently contrasts the blues. Truth be told I did not pick this cloak for its stats as might and agility were of absolutely no use to me, but I really wanted to have it for its cosmetic value.
If you want to know where a certain armour piece or cosmetic comes from, you can look it up in the Lorebook, by typing its name into the search box.
Head: Hood of Night, indigo dye (Halls of Night instance barter reward, cosmetic)
Chest : Robe of the Learned Stag, navy dye (Dunland quest reward, light)
Shoulders: Padded Mantle of the Dunland Soothsayer, indigo dye (Dunland quest reward, light)
Hands: Leather Bracers of the Gentle Stag, indigo dye (Dunland quest reward, light)
Feet: Embroidered Shoes of the Dunland Healer, navy dye (Dunland quest reward, light)
Back: Hoh-Dreng, rust dye (Vol.III, Book 4 reward)