Just open up Pixel Spy, examine the color of one of the pixels and enter the values into Photoshop's color picker. You can also do the same thing with any application that uses Apple's color picker. It is also particularly useful for determining the color hex codes needed in HTML documents, as you can determine the code for a particular pixel as well as quickly try out different combinations you come up with by altering the values manually. Pixel Spy also comes with a set of color lookup tables, or CLUTs, each of which contain a set of colors. After picking a color from the screen, Pixel Spy will notify you if the color is not in the currently selected CLUT, and can pick a color from that CLUT closest to the one you selected if you wish.
Usage is simple.
The selected color will be copied to the current color swatch and the color's values will be displayed in the various fields in the window, where you can transcribe them into whatever program you want. If you want to grab a color, you can hit the color capture key to stop the updates, or just pause the scan for the same effect. You can also manually enter values into any of the fields to come up with your own color. As you enter the values, the displayed color and value fields will update themselves dynamically. If you happen to have a CLUT you' d like me to include, just drop me a note.