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.)

Interestingly enough, organic LED (OLED) technology uses dyes instead of semiconductor materials. OLED display panels can be 'printed' like ink-jet printers. http://en.wikipedia.org/wiki/OLED

A dye is a colorful substance you soak things in to color them.

A die is either a regular polyhedron with numbers on it, used in games, or a device for cutting/molding metal into a specific shape.