Correcting colour casts

I recently read an email post by Tim Grey on how to correct strong colour casts and thought I would demonstrate it here.

In this image one can notice a pink and green cast across two of the eggs, especially if you look at the lower righht egg. 

To remove this cast one does the following

1. Duplicate the Background and rename this layer Colour Correction

2. Ago to Filter>Blur>Average. This averages the colour values of the image and this is the colour of the cast.

3. To apply the opposite colour value to this since to remove the cast, go to Adjustments>Image>Invert.

4. Then above the Colour Correction layer apply the Blend mode 'Colour'.

5. Use the Opacity slider to adjust the strength of the blend until you have the original colour minus the cast, as shown in the image below.