General Questions

For re-coloring the Atma Weapon 100%, assuming we're indeed talking about the weapon and not the monster, in FF3usME's Item Editor go to the weapon animaitons tab, then scroll down to items #91 and #92, the Buckler and Heavy shield. Those two shields there are actually what's coloring the Atma Weapon's 2nd and 3rd longer size! Item #29 is the shortest length of the Atma Weapon only.

Not sure if this helps whatever problem you've created for yourself, but it's good info to know nontheless.