Use leather armor only
Open a crafting table or your inventory crafting area
Place the leather armor piece and one or more dyes in the crafting grid
Take the dyed armor from the result slot
Repeat with additional dyes to change the color
Use a cauldron with dyed water if playing Bedrock Edition
Fill the cauldron with water
Add dye to the water
Use the leather armor on the cauldron to dye it
Use a dye on already dyed leather armor to recolor it
Dye leather horse armor in Java Edition by placing it with dye in a crafting grid
Dye leather armor pieces separately for different colors