It's actually impossible for that very reason. Most home users do not color calibrate their monitors - just be glad that the drills don't look purple! However, an expert with Photoshop and the right tools can get "as close as you can get" given the limits of web tech. I have used the Pantone color system successfully - and a physical sample whenever possible doesn't hurt. FYI.
Originally posted by Norm:
It's really hard to match the exact shade on the website, especially since different monitors show colors slightly differently.
--<br />Farlo<br />Urban Fey Dragon, Eater of Cookies