[Figs]

They're talking about this kind of "die": http://en.wikipedia.org/wiki/Die_%28integrated_circuit%29 ; "dyes" are substances used to color things. (See: http://en.wikipedia.org/wiki/Dye )

The book referenced as the first source on the "die" wikipedia link claims:

> The plural of die is dice. However, it has become standard practice in the industry to use "die" as the plural.

As a native speaker of English, I'd find any of "die", "dies", or "dice" to be pretty reasonable as long as it's clear what's referred to from context. (I'd prefer "dies" over "dice" if it's not immediately clear that you're not talking about playing dice, for example.)