What version(s) of WoW are you using?

Retail

What problem are you experiencing that led to you asking for this feature?

I'd love the ability to change to opacity of gear that is not your character's type, (ie: cloth/plate ect,) and weapons/off-hand items you can't use, (ie: dagger/sword)

What solution would you like?

just a slider and/or text box to enter the % value somewhere in the options menu.

This option will highlight unusable gear/items: