Optical multiplexing impacts widely in photonics, life science, biomedicine and engineering. Despite intensive efforts, current technology is limited by a longstanding “multiplexing ceiling” from existing optical materials. Here we engineered a novel class of polyyne-based materials for optical super-multiplexing. 20 distinct Raman frequencies are achieved as “Carbon rainbow” through rational engineering of conjugation length, bond-selective isotope doping and end-capping substitution of polyynes. With further probe functionalization, we demonstrated unprecedented 10-color organelle imaging in single living cell with high specificity, sensitivity, and photo-stability. Moreover, optical data storage and identification are realized by combinatorial barcoding, yielding the largest number of distinct spectral barcodes to date. Therefore, these versatile polyynes hold great promises in live-cell imaging and sorting, high-throughput diagnostics and screening, and information technology.