Can witches see octarine?

Question

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?

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^* Alternatively "colour", for my friends across the pond.

Answer 1

Tiffany sees a flash of what is almost certainly octarine in ,The Shepherd's Crown, in chapter nine:

There was a pregnant pause as the two eyed each other up - and Tiffany could have sworn she saw a quick flash of fluorescent light, greenish-yellow-purple - and then all was suddenly calm, as if there had been an agreement signed and sealed.

This greenish-yellow-purple light matches the description of octarine exactly - in The Colour of Magic it says:

It is said to be a sort of fluorescent greenish-yellow purple.

So it certainly appears that Tiffany, a witch, can see octarine.

Answer 2

Witches can certainly perceive high magical fields. This is referred to as "octarine vision" and any mage (magic user) has it, regardless of gender.

The Discworld RPG, developed in consultation with (and with the express approval of) Terry Pratchett contains this segment about "Octarine vision".

OCTARINE VISION

Magery, at any level [note that a full witch would have Magery Level 2, a trainee witch would have Magery Level 1] grants the ability to perceive magical energies by sight. Wizards often talk about this as the ability to see octarine. They say that it is granted by the presence of octagons as well as rods and cones among the cells of the eye. It is certainly true that magical adepts can see octarine, while other humans usually cannot, but witches, who work with subtler and less luminescent effects, rarely mention the subject; they just know that they see things that other people don’t.

Some even claim it’s just a matter of common sense and concentration. Whatever it is called, the ability certainly enables the possessor to perceive all sorts of supernatural phenomena, including beings with Psychic Invisibility. This sensitivity does seem to require a little training to be useful.

It also sometimes seems to be genetically inherited (although Disc heredity is complicated and self-distorting, or at least determined by personal background and very basic character traits. Thus, the wizardly line about the octagons may be a metaphor - or perhaps they grow as the result of training.