History Brush on Photoshop CS3: Make a Black&White Image with coloured areas

Open an image in Photoshop CS3.



Edit the image as necessary. Open the Image->Adjustements->Black&White in order to get a nice b&w image.



Click on "History" and click on the little square on the left of a status of the image just before the black&white conversion. This status will be taken as "Source" for the "History Brush".



Now come back to the image clicking on the last status. Select the "History Brush" and "paint" an area of your image.


You'll see the area coming back to its original colour!