So being able to customize the appearance of your armor is pretty awesome (Haven't gotten to try it myself, sadly)! For a game with so many gorgeous weapon, armor, and clothing designs, being able to choose your favorite appearance is Godsend!
However, the current system feels a bit... messy. Not only do you need to still have the items on-hand, but you have to "apply" them to each individual piece of gear, using this other sort of pseudo-currency, which you have to do a quest to unlock... it feels like it needs to be streamlined a bit.
Here are a series of suggestions I would like to put forward that I would would really improve the system. Hopefully, you guys agree!
1. Add an entire "Vanity window" to the UI. In it, your character is loaded up as they are on the Left side of the window, and you can play around with their appearance in the Middle of the window, without changing your actual appearance. When you're satisfied, at the bottom-right of the window you can either click "Cancel", or "Accept" which would charge you for whatever changes you've made..
2. On the Top-Right side of the screen, would be a group of icons representing each visual Equipment-Slot, including Weapon and Off-hand (the latter being greyed-out if you don't have one equipped). Upon clicking an icon, a list would appear directly below it, displaying every eligible item of that type you can use the appearance of for that slot.
3. Upon clicking one of those items, the character-model in the Middle would change its appearance to that item, while the appearance of the Left model would remain remain unchanged.
4. Along the very top of the window would be several tabs; Style - Color - Sets. Style is the tab is would be on by default, while clicking Color would change the list on the Right from being weapon and armor styles, to different colored Dyes (with a "Default" option at the top of each list, to return said item to its undyed state). If necessary, the "list" could be split into two halves, one as a Primary color, the bottom controller the Secondary color (I've never dyed an item, so unsure how much detail is necessary).
5. Once you're done customizing your appearance, you can either click "Accept" or "Cancel" on the bottom-right of the window. Upon clicking Accept, you'll be prompted with a window, saying what the total cost is, and also whether you'd like to Save the appearance for later use
6. Clicking the "Load" tab allows you to quickly access any custom Sets that you've Saved. Clicking one of these sets will replay a preview of the set in the Middle. If you're looking at a set with items you're not eligible to wear (ie. weapons, heavier armor-types, or Job-specific armor), the icons on the top-right of the screen with light up with a flashing red color, and the preview will just revert to your equipped items in those slots.
7. To unlock new "Style" options, you need only equip an item with that item's appearance, and it automatically "unlocks" that appearance across all of your characters. To use a particular style, however, you must still achieve the minimum Level to equip it (ie. some armor-designs are present at lvl 20-ish and beyond), and also any Class/Job restrictions (so no Dragoons running around in armor for a Black Mage). This would also apply to "Special" items, such as Lightning Returns event rewards, so that you can use the armor on alts who didn't complete the event (provided to acquired said items on at least one character).
And... that's pretty much it. It's a long-winded explanation, but I think in practice, it would be really simple and a lot more user-friendly. So, what do you guys thinks?