Exploring color matching in JavaScript [2013 post brought back from the dead]

I wrote this post back in 2013 for HTML5 Hub, which later became the Intel Developer Zone. The site’s gone through many changes over the years and this post is no longer there, so I figured I’d repost it here instead. This is mostly unedited from the original posting, except for some extra headings and removing one dead link from the final section. The following should also show, for the record, that I used dashes before ChatGPT thought it was cool.