It's not normally possible. It is, however, doable with certain NPC models such as is present in the modified avatar models that were edited to remove the heat haze effect... Unfortunately this is not transferable to 'normal' equipment, and I was unable to make any further progress. It seems to be something that is present in the top-level header that determines which alpha effect is used (transparency, shine, translucency).
Modified Avatars Link
Not bad and I like the color, but you might want to consider giving the embroidered parts a gold color or something similar. The blocking on the dark part of the pants is something that is unfortunately present in the original model but much more apparent on something red, so that would have to be traced with an airbrush or something on a new layer to be fixed.
XI Wiki



