They have to be in your personal inventory also, not the bank, or shared bank or whatever.
If you wanted to make it yourself, do the Crescent Brewing and Pottery training quests. Don't need to do the turn ins, just keep getting supplies until you get to the trivial for the recipe, then remove the quest and get the next one, upto skill 54 in each. That's enough to be fairly successful at making the dye. Here's the recipe: http://eqtraders.com/items/show_item.php?item=7878&menustr=035000000000 Use the Pottery and Brewing skills, and not the Alchemy combine, unless you happen to be a Shaman working on Alchemy. All the supplies are available in the Gulf of Gunthak (PoK Gunthak stone on south / evil side, west wall) with the NPC near the Banker in the lighthouse, so not hard to stock pile stuff and run back to PoK or where ever you want to do the combines.
It's easier to just buy it though, and generally not more than 50p, and it costs around 30p (if I did my math right, 10.5 + 10.5 + 8.5 + 0.02 or something like that) to make without failures.
Just a couple of notes, I didn't see mentioned.
Yther Ore.