I have been using a handy little utility to find the HTML/RGB for colors I have come across during web browsing to use in my own projects. It's called Pixie and is extremely light weight but gets the job done.

" Pixie is an easy-to-use, fast and tiny utility designed especially to fit the needs of Webmasters and Designers. Its a colour picker that includes a mouse tracker. Run it, simply point to a colour and it will tell you the hex, RGB, HTML, CMYK and HSV values of that colour."