How to use dye

[OneNineDeepSilence]

The game doesn't give any error and there's no info about this in help or any results on web so far, so I'm placing this here:

Apply the changes to unlock each dye -- ONE by ONE, to just one part.

To do that click on "Purchase" button at bottom, which is misleading since you already need to have the dye in inventory to apply it to an outfit (that you own already).

To know how much dye you need, pick the color you desire (it's more expensive to pick a custom color, but you can see the difference at bottom).
Also first preview the full outfit with all dyes applied, should do this before buying the outfit, to see if all parts can be dyed and how much (some colors will blend into existing materials or colors), and some parts will remain at default color (the green gems on Ruler of the North outfit for example).
Then write down which colors you want for each part and how much they cost (or more exactly how many dyes are needed for each part). Then buy the dyes in cash shop for Lucent or the other event special coin (whatever is called).

When I changed some colors second time, I could unlock two dyes at once. But for the initial change, could not apply 2 or 3 dye changes, the game just said that "Outfit is saved" and returned to default colors, without using the dyes from inventory. Only when tried to apply 1 dye unlock/change finally worked and applied the change and used up the amount needed.

[Rigs]

The game doesn’t give much of a clue about anything. I would also like to know the answer to this, though