This paper describes our experience in building a lowcost spectrophotometer called Colortron, initially available on the Macintosh platform. It discusses both technical considerations we faced in building the device as well as what we've learned about the uses of such an instrument.
Rob Cook, "The Power of Spectral Data" in Proc. IS&T 2nd Color and Imaging Conf., 1994, pp 57 - 57, https://doi.org/10.2352/CIC.1994.2.1.art00016