This is a personal project trying to solve this question: What is the exact color (RGB) when given a spectrum? As we know, a spectrum is the only way to describ a color without any ambiguity. Given a spectrum we can see and repreduce a color exactly the same, theoretically.
I have write a series blogs explaining the outline and details of the whole thing. You can checkout these blogs at OpticPhantasm, my special column at Zhihu.