In many of the Discworld books focusing on wizards, it is often mentioned that only wizards can see octarine, which is the color* of magic. However, I cannot recall it being mentioned in any of the books that focus on witches that witches can see octarine. I suppose this could be because witches tend to be less flashy than wizards and don't need to go about telling everyone they can see colors that others cannot. But, given that wizards and witches have other unique things in common (for example, they are both visited by Death himself when they die), I would expect that they can both see octarine.
Is there any mention that witches also have the gift of seeing octarine?
* Alternatively "colour", for my friends across the pond.