The gamma/curves tools don't enter into it. It's simply a hue number applied to a sprite, they don't take the sprite out, edit it in photoshop, then put it back in. They don't "strip" the colours out of a sprite before rehueing it, they simply change the palette it uses. In effect it's like whitewash; all the detail and interest is lost.
Check out InsideUO. It has all the sprites in their natural colours. Open up an animation, click the little button to change the colour, and you will see the palette options. Pick one and voila, the sprite is rehued. All they do to the mob is is change the palette by referencing a hue number. No editing of the original pixels occurs.
The only sprites that appear "stripped" of colour before rehueing are the ones that are designed to work that way: forest & frenzied ostards, lava lizard, bird, bullfrog, slimes, characters, hair, clothes. No horses, no dragons, no llamas, etc.
I'm wondering if this survey will be offered to all players via some in-game vote, or is it exclusively for the minority who read Stratics. Remember, we're not making decisions based on minority opinion...