I am working on an app that saves canvas content as a raster image, then user saves it to his computer to print with a printer or print office. If you visit the link, you can click button Export and click the link to save the file. I know I can't handle CMYK with canvas and the file is sent as RGB. But I can control color values that are used for generating the image. For example, if I know that some object is any shade of black, I can put it on a separate layer and then join black layer and colored layer together on server side. May be it can help with the issue. So, I wonder if any of you faced a similar challenge to generate color-accurate image ready for print with canvas. Or may be using SVG can help me by any chance? Please share your hints.
Note: I use Python as a server-side language but I think any language library/solution will work for me if it does the job.