A colour cast is a tint of a particular colour across an entire photographic image. Many old photographs suffer from colour casts, particularly of an orange hue. These can easily be corrected by scanning to create a digital format, then either adjusting the white balance, or manually adjusting the levels through Adjustments > Levels. Correcting a batch of nostalgic photos can be a very satisfying task as familiar images come to life and reveal details never seen before simply by removal of a colour cast and enlargement of the image as a whole.
Below is an example of an image that has had it’s excessive red colour cast removed.