Strictly technically speaking, yes, PDF (beginning from version 1.3) supports alternate images (eventually from remote resources) with different resolutions and colour spaces in order to let the PDF viewer choose which version to use depending on the destination device (screen, colour printer, grayscale printer). Certain substandards (e.g. PDF/A) might not support these feature, though. (See Section 220.127.116.11 Alternate Images, Document management — Portable document format — Part 1: PDF 1.7, Adobe Systems Incorporated, 2008)
In practice though, unfortunately, there seems to be no support for this valuable feature in the Latex- or "open-source PDF"-World, so to speak. Some professional proprietary products (e.g. Adobe Illustrator) do support this feature though. Supposedly creating the "dual-colour-space" images/figures in Illustrator if possible and including those PDFs in your Latex-Document might produce the result you are looking for... maybe.
A trade-off between native alternate images and multiple versions of the document (latter of which is not suitable for paper submission to conferences, e.g.) could be Optional Content Groups (OCG) (starting from PDF 1.5... I think). Those can be produced with the package
ocgx but would still require the user to select the correct layer/OCG (colour vs. grayscale e.g.). OCGs are not (yet) supported by all viewers, but those viewers known for maximum coformity (e.g. Adobe Reader, Foxit Reader, Okular) do support OCGs.