ColorSafe 1.0 Beta is an open-source stand-alone program which converts color values from hexadecimal to RGB triplets, and vice versa. You will be able to use ColorSafe to view the nearest web safe color according to the values you have specified.
RGB triplets can be entered as floating point or integer values, providing support for the Arithmetic and Decimal RGB Color Models. ColorSafe makes selecting colors easy by providing RGB, hexadecimal, HSB and CMYK percentage information for all colors within the standard RGB Color Space. The Palettes accessed from the View menu allow the user to quickly choose from X11, grayscale, windows system, named and web safe colors.