The Extra-Strength Tips for the Clients and Friends of Ben Willmore (www.digitalmastery.com):

This time around I'd like to share with you a few ideas of how to think about color in Photoshop.

Right now, head on over to Photoshop, open any RGB mode image and choose Window>Info. That should make the Info palette visible somewhere on your screen. The Info palette measures the color that is currently under your cursor. The left side of the Info palette usually reflects the mode your image is in (RGB, CMYK, etc.). The right side is usually set to display CMYK numbers. You can change how Photoshop is measuring color by clicking on the tiny eyedropper icons that appear next to the numbers in the Info palette. Since you have an RGB image open and probably have the default settings, your Info palette should have RGB on the left and CMYK on the right. If that's not the case, then click on the eyedropper icons I mentioned a second ago and set the left to RGB and the right to CMYK. Now let's figure out how the Info palette can help us to adjust the colors in our images.

Let's look at the relationship between the right and left sides of the Info palette (assuming you have them set up like I mentioned in the previous paragraph). The left side of the palette will measure things based on light--Red, Green and Blue light that is--while the right side will use ink. The C in CMYK is directly across from the R in RGB because Cyan inks' sole job in life is to absorb red light. M is across from G because Magenta ink absorbs green light, and Y is across from B because Yellow absorbs blue light. If that doesn't seem to be all that exciting, then try this:

With any RGB mode photograph open, choose Image>Adjustments>Curves. When Curves appears, click anywhere on the diagonal line that appears and drag up or down. Dragging up should brighten the image (adding light), while dragging down should darken the image (taking away light). When you're done playing with that dot, then drag it off the grid area to get back to normal. Now, let's see how we can use one of those dots to shift the color of an image.

Change the Channel menu that is found at the top of the Curves dialog box to Red and try the same dot experiment. You should notice that moving the dot up towards the word Red (that's at the top of the Curves dialog box) makes the image more red, while moving it away from the word Red will make it the opposite of red, which is Cyan (remember C is across from R in the Info palette, which indicates Red's opposite is Cyan). Next, drag that dot off the grid, change the menu at the top of the Curves dialog box to Green and do the same experiment. You should notice that moving the dot up towards the word Green makes the image greener, while moving it down makes the image more magenta. Finally repeat the experiment with Blue chosen in the pop-up menu. Now do you see how the Info palette can help you to figure out what will happen when attempting to shift the overall color of an image?

Ok, now let's get our adjustment to be much more concentrated on an area of the image we'd like to work with. With the pop-up menu at the top of the Curves dialog box set to Red, move your mouse over the image and hold down the mouse button. You should see a circle appear in the Curves dialog box. That circle indicates which part of the curve you'd need to change in order to concentrate your adjustment on the color your mouse is over. To add a dot where the circle is showing up, hold down the Command key (Mac), or Ctrl key (Win) and click on the image once again. Once the dot is added, use the up and down arrow keys on your keyboard to shift that area of your image towards Red (up), or Cyan (down). You can repeat this process on the Green and Blue curves to shift the overall feeling of an image (warm, cool or neutral) towards any color you desire. In your next tip, I'll expand on the ideas we talked about here and you'll learn how to apply these ideas to adjusting skin tones.

Now, if you want to learn how to really understand color, you'll need to check out my new 2+ hour long DVD on color manipulation. Visit www.digitalmastery.com/dvd for details.

-Ben Willmore