Selecting matching colors for your web sites and ebook projects can become laborious job.
Personally, I want to know quickly what a particular color will look like as the background color for a web page.
I also want to instantly see matching colors and have the hex codes ready to copy and paste.
html-color-names.com has a color chart with 140 HTML color names:
Each page links to the color name where you can see the color as the background and get the html hex code. Each color name page also contains matching colors and hex codes.