olfarve VS PEASS-ng

I'm always looking for formulas around brewing and beer, with the goal of eventually building my own brewing calculator. At the moment, I'm tinkering with the topic of beer color, especially the rendering of color impressions of SRM/EBC values. Unfortunately, there isn't that much published material, so I started poking around in the source code of some brewing calculators. They often use either fixed color tables obtained from beer color charts, or polynomial functions fitted to the color gradients of such tables. Finally, I came across some decades-old forum posts by A. J. deLange, who also happens to be a member of the BJCP Color Guide Committee. He has published a mathematical model that describes the average spectral properties of 99 beers and can be used to reconstruct a spectrum for a given transmission path (e.g., the width of a beer glass) from an SRM/EBC value. This spectrum can then be transformed to coordinates in the CIE XYZ color space and mapped to another color space such as sRGB to display on a computer screen, for example. Since the process involves some non-trivial math and color science, I've decided to make some reusable source code available in a GitHub repository (yes, that includes an Excel spreadsheet): https://github.com/aschet/olfarve