Colour cast

[1] Certain types of light can cause film and digital cameras to render a colour cast.

Colour casts can also occur in old photographs due to fading of dyes, particularly under the action of ultraviolet light.

If a filter is unavailable, using a flash is an alternative solution which usually provides enough neutral white light to counter the cast.

In the case of film, if photographs all contain the same cast, it is usually indicative of improper chemical development.

If the film itself does not contain any cast, it can be reused to create another set of photographs in proper chemical conditions.

Example of a photo with a uniformly green colour cast due to differential absorption of light before reaching certain depths at sea.
The same photo with the colour cast corrected