Blue dye is a dye made by Aggie the Witch or Ali the Dyer from 2 woad leaves at a cost of 5 coins. It can also be purchased from Oronwen, who owns the Lletya Seamstress.
Woad leaves can be purchased at Falador's park from Wyson the gardener or grown using the Farming skill.
It is used to turn capes and wizard hats blue in colour. Players can combine it with red dye to make purple dye or with yellow dye to make green dye. Players can also make Black wizard hats blue, by using the dye on them.
It is also used in some quests. For example, it is used to dye goblin mail in the Goblin Diplomacy quest and it also could be used on the Ghosts Ahoy quest to paint a toy boat.
Some players believed at one time you could dye party hats; however, this is not the case, and it was simply a rumour.
| Standard | |
| Treasure Trails |
 Barrows Shadow Third-Age Blood Ice |
| Other |
 Black mushroom ink |
