change a photo color using rgb

Can you select a color on a photo and change just that color. If the photo has several areas of a certain color, can you change that color either in the palette or through an option, and as a result change all areas on the photo that contain that color?
I would like to change the color using a RGB value.
Optimally, I would like to select the color on the photo, by selecting one area which contains that color, change the RGB values for that color, and as a result have all areas with the original color change to the new color. Hopefully you do not have to select all of the individual areas, which would be impossible on a complex photo or image.

There should be an option called Replace Color... under the Image Tab.