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Does webkit/wkhtmltopdf not support icc-color profiles in fill colours in SVG images?

I have an image that has the colour defined as:

#e22e27 icc-color(U.S.-Web-Coated--SWOP--v2, 0.0558938, 0.95947204, 0.98716716, 0.00204471)

Which is supposed to come out red (and does in inkscape)

However, chrome (and other browsers) just open it as black (I'm guessing because it can't get the fill colour?) and also wkhtmltopdf also comes out as black.

Is there any way of doing this? Or more specifically is there any way of defining a device spot colour in the SVG so that the final PDF can have a spot red (rather than a composite of RGB)?

Thanks

TheStoneFox
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1 Answers1

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if you open the SVG in Inkscape 0.92 after removing the sRGB value #e22e27 I expect you will see black instead of red. This is because even when using the CMYK colour picker, Inkscape reads and writes fallback sRGB values from/to the SVG file. Native CMYK support is still in Inkscape's future, as far as I can tell.

Among the open source PDF renderers, mPDF supports defining spot colours by CMYK values and also supports embedding a subset of SVG in HTML, suggesting that it can read some SVG syntax natively. This would be a better starting point for a fully open source solution than wkhtmltopdf which does not support CMYK output at all, according to issue #39 on its GitHub project.

Of the proprietary renderers, PDFreactor supports passing CMYK values from an SVG directly to the renderer as long as they are not rasterised, although the syntax does not appear to match the W3C SVG spec and there is no sRGB fallback, so each SVG has to be specially crafted. This is quite easy for simple graphics originated in Inkscape; just replace for example in your SVG:

style="fill:#e22e27 icc-color(U.S.-Web-Coated--SWOP--v2, 0.0558938, 0.95947204, 0.98716716, 0.00204471);fill-opacity:1;fill-rule:nonzero;stroke:none"

with the C, M, Y, K values only:

style="fill:cmyk(0.0558938, 0.95947204, 0.98716716, 0.00204471);fill-opacity:1;fill-rule:nonzero;stroke:none"

I've recently used this technique in an attempt to match colours between SVGs and CMYK values specified in CSS for the document, for example between logos and font colours. See CSS Color Module Level 4 for the emerging device-cmyk syntax; in the meantime PDFreactor uses the non-standard cmyk syntax for CSS, as shown in the SVG example above.

In general, I'm wondering about the value of embedding a colour profile in a natively CMYK SVG. Perhaps the assumption is that we are starting from an sRGB value and need an approximation of it, but in my workflow I'm starting from CMYK values. I'd welcome clarification on that. Besides, it would be rather time-consuming to re-create every SVG file just because the printing machine, continent or paper has changed.

Daniel James
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