You can find various dye merchants spread throughout Ghost of Tsushima, normally spawning near Survivor Camps or other populated locations. However, there are two dye merchants that are off the beaten path, and you'll need to find them both for the Monochrome Masters Trophy.
White dye merchant
The White Dye Merchant can be found west of Wanderer's Pass, in the Izuhara region in the area where you will start the game. It's a bit of a climb, in a fairly secluded region, but there will be a golden bird there to guide you when you get close enough.
The White Dye Merchant will sell the following items:
- Nine-tailed fox skin for the long bow for 5 flowers
- White armor dyes 10 flowers for Traveler's Outfit, Ronin's Outfit, Kensei's Armor, and Gosaku's Armor
- Pure Intent Headband for 20 flowers
The armor dyes will be locked behind the armor themselves, as the merchants dye the armor for you, you can only buy them if you already have the armor unlocked.
Black Dye Merchant
You'll have to wait for Act 2 to access the Black Dye Merchant, as it's only found southwest of Urashima Village, east of the Toyotoma region. It will be in a cave behind a large patch of bamboo, but you will be able to tell its location from all the black cloth leading up to the cave.
The Black Dye Merchant sells the following items:
- Skin of piercing shadows for the half-bow for 5 flowers
- Black armor dyes for 10 flowers for Tadayori armor, Traveler's outfit, Sakai clan armor, Goasku armor, Ghost armor, Kensei armor
