(edited by Grover.8753)
Dye consumed itself without authorize
There is no way to ‘rollback’ your account for just a minute. Sometimes items end up in a ‘limbo’ between Inventory and the Guild Bank. It is quite common. The solution is to change maps/drag some other item out of the bank/change characters/relog/etc.
You can try these and see if your dye re-appears. You can contact the CS Team and seek assistance using the ‘Support’ link above/below and ‘Submit a Request’.
Good luck.