Background blur
level: advanced

Faking it: depth of focus

Load both pictures. One will obviously be the reference photo, and the other the one you want to look similar.

We have chosen these pictures. They don’t look very good but will do nicely as illustrations.

This is the reference image:

And this is the one whose greenish sky we want to look like the one in the reference picture.

Before starting the procedure, make sure you have the second picture selected, not the reference image.

Click Image/Adjustments/Levels or press Ctrl+L. You can see three eyedropper icons on the right side of the dialog that appears. Double-click the middle (grey) one to display a color picker dialog.

Drag it somewhere on the desktop so that it doesn’t cover any of the important areas of the reference image. Bring the mouse pointer off the dialog. It changes to an eyedropper. Click a color in the reference picture. You should click a characteristic color, this time, the blue of the sky.

You’ll see the selected color on the palette. Now click OK to return to the Levels dialog. Once again, bring the mouse pointer off the dialog to change it to an eyedropper. This time, hover it above the area that you want to match with the selected color, in the photo to be modified. Of course, in this example this will be the same area of the sky. Click this area to change the color levels in the picture. Make sure to select an area of approximately the same brightness as the one you have used to take the sample. Also, the color you want to get should be similar to the sample color. You can easily observe the changes after clicking. If you are unsatisfied with the result, that is, the color levels are not like those in the reference image, click somewhere else near the previous spot, or some other area of the photo, until you get the image look like you want.

Click OK on the Levels dialog, when you are ready. As you have changed the mid-grey tone during the procedure, a message asks whether to use the newly selected color as a default from now on. Click No as we only needed this blue in this particular procedure. Leave the original mid-grey as default.

The result shows a less dominant greenish veil and a sky that sports a color more similar to the reference image.

Related Photoshop Tutorial:

Color matching (hungarian)