Not a bad idea, as well as allowing to do the same thing on an armour transmog, and it applies the rest of the transmogs from that same set/appearance in the other armour slots.
I think the wardrobe is going to need a bit of an overhaul/improvement sooner or later. That tiny little window to browse the items is already feeling super small and claustrophobic.
Still waiting for dyes for weapons and mount armours/bardings. It’s so silly they design mount armours that go with character armour/transmogs but then the mount armour is only available in the default colour, so you are forced to keep the default dye colour for the character transmog, if you want it to match.