On Jun 3, 2009, at 10:49 PM, Mathew Oakes wrote:

LittleCMS doesn't matter particularly as the answer to the original question from Terry Brown. Printing as SPOT colour, means output separations for named colours individually, not mixed as CMYK, RGB, LAB or anything else.

LittleCMS actually does matter.

It gives support for *previewing* output results, for detecting out of gamut colors, and even for using named color icc profiles. The latter is probably the primary way to reliably and portably denote spot colors, but SVG hasn't integrated direct use of them yet.

A functional work-around would be to have an icc profile with a single number input, and that does an effective index into a set of spot colors. A bit strange, but should work with Inkscape 0.46 as it was released.