When determining the color scheme for the photo (meaning choosing clothing, props, and background), dissect the color elements in your mind. This will help pre-visual the outcome of your photo session. (BTW, this takes years of practice.)
We also extract the color of photo for web design. The photo and the web colors must compliment so this is how the analysis of color happens.
Not everyone can "see color", ColourLovers.com is a great place to see color swatch suggestions. Here is a fun animation from ColourLovers.com.