This will only be of interest to those who need to describe colours (of fungi) in a formal way.
When a new species is described, it is traditional to include colour information by referring to a standard colour chart. Modern publications may contain accurate full colour images of the species, but nevertheless there is still a role for these standard colour charts. The standards charts, like Methuen, Ridgeway & Munsell, are difficult to get hold of, and expensive. Here is a simple Excel spreadsheet that allows you to cut & paste a sampled colour, as the hex code, and find the nearest matching colours in several of these standards. The accompanying document describes the background to the tool. The spreadsheet uses code and you will be prompted to enable code execution.