Color management through ICC Profiles has become common place for soft proofing, where CMYK images are transformed through 4-dimensional lookup tables from CMYK to CIE-L*a*b*, then through the system's monitor profile to calibrated RGB. When more than 4 colors are used it becomes impractical to print n-dimensional targets for n-dimensional ICC profiles and the n-dimensional lookup tables for device space to profile connection space in these profiles become extremely coarse. The latest generation of graphic cards contain highly parallelized processors (GPU) which can now be programmed through high level languages like Cg or GLSL. This paper describes a GPU based approach which combines 4-dimensional interpolation for CMYK with a spectral mixing model for n additional colors.
Franz Herbert, "Soft Proofing of Multi-Color Documents in a Panoramic Environment Using Real Time Spectral Processing" in Proc. IS&T 13th Color and Imaging Conf., 2005, pp 320 - 320, https://doi.org/10.2352/CIC.2005.13.1.art00061