White Powder

I've looked at it- I plan on hunting Desert Giants (Sand Golems on that list. At least, I hope they're the same. XD) for them, since they're in Ariant.

I'm not exactly sure what training areas are suggested for each class though, so I have no idea if people train on those monsters or not.

They have pretty bad spawn so no, not really. on my aran I had 90-something white powders and less than 20 of every other color. Seems to me white is quite a bit more common than the others since it is needed so much.