Detect a color from a picture?

PS CS3 10.0

Is there a way for PS to detect a color from a photo instead of you manually trying to find a color to match?

I'd like to add color that's already in the photo, but I'm having a hard time trying to figure out the shade manually.

Thanks for the help!!

Eyedropper. That's what it does.

If I am understanding what you're asking.