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If by "illustration technique" you mean blue-for-black, it's as old as comics -- and by "comics" I mean not just the half-tab format that wears the name today, but all the way back to the newspaper comics, our venerable ancestors.

It's a side effect of the four-color (CMYK) process, and the limitations imposed by it. Even if a colorist was skilled enough to coax a wide range of effects out of the limited pallette, the work was still filtered thru the separators, who sometimes followed the guides, sometimes didn't. (You can find Prince Valiant, for instance, sometimes with pale gray highlights on his black hair, sometimes white, sometimes blue, sometimes blue-gray.)

In comic books, which were from the beginning the redheaded stepchild of "real" publishing, even less care was taken, and "shorthand" often became "shortest possible". Thus, Superman has blue highlights, and people say he has blue hair.* Even tho Lois also had blue highlights. (Perhaps people thought that was a rinse?)

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