40 smalls? You need to wait for the Aether quests then. Gives you around 55 or so smalls. Outside of the quest, there are no plus value offers for aethers nor any that let’s buy 40 smalls.
Your best bet is seasonal offers like this or this or Break the limits.
The most you can get of a particular color is again during the quests Aethers Aplenty. Barring that, Great Power let’s you choose a color but again, not the quantity you’re looking at.
The web store may come up with aether offers in near future so keep an eye.