Here’s another way to reduce purple fringing using Hue/Saturation instead of the Lens Correction filter
Photoshop’s Lens Correction filter is capable of reducing purple fringing (aka Chromatic Aberration), but doesn’t always give perfect results.
Purple fringing is the term given to a colour edge that appears in high contrast images, usually most noticeable in landscape images with white sky against trees.
To do this, drag a basic rectangular marquee selection over purple fringing and then add the Hue/Saturation adjustment layer.
Zoom into the area and click on the hand with arrows button in the adjustment.
Click on the purple and drag to the left to instantly reduce purple fringing.
All changes will only be applied to the area selected. Of course, you can use the Brush and Eraser tools to selectively edit away additional purple fringing throughout the image.