For each color in the preceding rainbow (and there are 6 of them), the RGB components are "golden ratios" of each other. Take for example the "red" first from the left:
rgb(100%, 38.2%, 61.8%);
r/b = b/g = golden ratio = 1.61803398875. Going through all the other permutations gives us all the 6 colors of the rainbow.
It is also possible to omit the
38.2% component, resulting in more vibrant colors:
The greens are particularly interesting, because they appear to be the least different from each other compared to the "reds" and "blues", and, to me, there is something soothing about the two colors at either end of the spectrum.
Colors originally viewed on an Apple MacBook Air M1 with brightness at around 50%.