Today’s Question: In Photoshop it is possible to acquire a color for a brush from the image itself, or even other places on the screen [using the Eyedropper tool]. In Lightroom Classic I don’t see a way to do this. Many times, I have wanted to paint with a color that is in the image but end up having to approximate by eye. Dragging outside the color picker doesn’t work as it does in Photoshop.
Tim’s Quick Answer: In Lightroom Classic you can sample a color from the photo you’re working on by clicking in the color picker and then dragging (while still holding the mouse button) into the image area. It is not possible, however, to sample colors from the Lightroom Classic interface in this way.
More Detail: In Photoshop it is possible to sample a color from an image, or anywhere in the Photoshop interface. You start by selecting the Eyedropper tool, which enables you to click within an image to sample a color from that image. In addition, however, you can click within the image, then drag the mouse outside the image to sample a color from anywhere within the interface, or even in areas outside of Photoshop.
In Lightroom Classic you can sample a color from a photo, but not from the overall interface. For example, with the Adjustment Brush tool in Lightroom you can apply a color to an image, along with a variety of other adjustments you can paint into specific areas of the image.
Toward the bottom of the controls for the Adjustment Brush (or the Graduated Filter or Radial Filter) you’ll find a label for Color, with a color swatch to the right of it. Click on that color swatch, and a color picker will appear. If you hover your mouse over the color picker, you’ll see that your mouse turns into an eyedropper icon. You can click within the color picker to sample a color.
To sample a color from the image instead of the color picker, click within the color picker and keep the mouse button down. Then drag the mouse into the image area, with the mouse held down until you have located the color you want to sample. Note that a small square on the color picker will indicate the current color under your mouse. When you’re hovering over the desired color, release the mouse button and that color will be the active color for the Adjustment Brush (or other targeted adjustment tool).
However, as noted above, while you can sample a color from within the image in Lightroom Classic, you can’t sample a color from the overall interface.