International Orange is a bright reddish-orange color used on the Golden Gate Bridge. The color was decided by consulting architect for the bridge, Irving F. Morrow, after extensive studies. He wanted a color that could blend well with the surrounding hills as well as provide sufficient contrast with the ocean and the sky.
The CMYK values of this orange vermillion color as suggested on the Golden Gate Bridge official web site are (0, 69, 100, 6). The closest Pantone® values are 173, 174 and 180.
Note: There are other tons of International Orange including ones used in aerospace and engineering. Please search this site for more information.