So after years of going blind trying to match on screen colors to those of the swatches on my desk, I have found two cheats.
the first is a swatch palette from Sherwin Williams that plugs in to photoshop. Obviously, it only works with Sherwin williams colors but 90% of the arch projects I work on spec either SW or MAB paints. After dropping the file into the swatches folder you can load it in your swatch palette and then if you select list instead of thumbnail you get the number and the name of the color. So no fighting with the client if the color is correct. Sherein williams has this as a free download so I'm attaching it to this post.
the other color helper is a website:
http://www.easyrgb.com/index.php?X=SEEK
sherwin williams site to download the swatch file.
http://www.sherwin-williams.com/pro/paint_colors/paint_color_samples/color_visualizer/index.jsp