That's the definition of aberration. Chromatic aberration is when you see unexpected color in an image. It is also known as color fringing. Fringe is an appropriate term because the color concentrations usually happen along the edges of the subjects in the image. Scientifically, we are talking about light wavelengths and how that light passes through the lens of the camera. You will see chromatic aberration often in high-contrast lighting, fast moving objects and in water environments.
How about an image taken in water, looking towards a strong light source (the sun) with a moving subject?
When you have an image with color fringing you want to correct, go to the Lens Corrections section in the Develop Module, and click on the Color tab.
First, enable the correction adjustments by checking the box by Remove Chromatic Aberration.
Adjust the slider bars for Amount and Purple Hue, or for the Amount and Green Hues. How much you adjust on either or both is completely up to the image's needs and your preference.
Choices at the Fringe Festival
Not sure what color or how much to adjust? Click on the eye dropper tool and hover over the color fringe area.
You will see this box appear:
The colors in this box will change depending on which part of the image you hover over. Click on the color in your image and the adjustments are made automatically.