I read How can I find out what RGB colors a website uses? and know how to spot a color on the website. There are several plugins available, and this topic is beaten to death on above stack page.
However, I want to know all the colors (hue to be specific) at tertiary level on color wheel used on the website (webpage to be specific) and the location where it is used. I don't want to get flagged for posting an XY problem. My goal is to figure out the color schemes, and how it relates to the product.
Essentially, I am trying to reverse engineer all the colors used on the website. This will also help me to augment any website by being consistent with the colors already used on the website.
As an aside, I researched this topic and found that there was a good discussion on fonts at How can I know what fonts a website is using?, but I couldn't find anything for listing all the colors.
I am a PC user and regularly use Chrome, Firefox