Sampling and Monitoring Image Colors

There are many times, especially in graphic design, when we want to use a color we find in an image. We have a tool for that: the Eyedropper tool. To have a live, ongoing sample in order to monitor colors as we make adjustments, we have its cousin the Color Sampler tool. Both have more depth than most users realize.

Eyedropper Tool

The Eyedropper tool reads, or “samples,” colors displayed on screen—and not just in Photoshop. Access the tool from the Tools panel or by pressing the letter i. The letter i accesses any one of six tools, so if the wrong one appears, press shift-i repeatedly to cycle through them.

Clicking on an area in an image with the Eyedropper tool changes the foreground color to the color that was below the tip of the cursor (its lower left end); holding option/Alt while using the tool changes the background color. Some users find the default cursor imprecise. The Eyedropper, like many tools, offers a precise cursor that you enable by turning on your keyboard’s caps lock.

Photoshop continuously reads color under the cursor while you hold down the mouse button, committing it only when you release. So if you press down the mouse button within an image, you can then drag the cursor anywhere on screen, in Photoshop or not, and the color under the cursor will be recorded when you release the mouse.

Sometimes, like when an image has a lot of noise, reading the color of one pixel, a “Point Sample,” may not be desired. By right-clicking with the Eyedropper tool, you can choose to average between nine (3 by 3) to over ten thousand (101 by 101) pixels. Be aware that this setting is sticky and will be retained until changed again. Also, and more dangerously, this setting affects other tools that sample color: the Color Sampler tool, the Magic Wand tool, and the Eyedropper tool that appears when using the Color Picker. Luckily, in each of these cases, you can see and change this setting in the Options Bar along the top of the screen.

Color Sampler Tool

At any time, and with any tool active, the Info panel will show you, in its upper left, the color numbers under your cursor. But sometimes you need to monitor a particular part of the image (or many parts) while performing an adjustment, for example. This is the job of the Color Sampler tool.

Each time you click in the image with this tool, you create a numbered sampling point. You’ll see each one’s number in the Info panel. When an adjustment layer is selected, you’ll see two sets of numbers: before the slash are the unadjusted values; after are the adjusted ones.

You can place up to ten sample points.

Color Samples & Soft Proofing

An interesting use of this tool is to monitor what potential CMYK values would be if we were to convert our RGB image to a specific CMYK color space. In a way, this allows us to do anticipatory adjustments to an image while it’s still in flexible RGB.