Blue light
In low light, in fog or rain, or at twilight the natural colour of the light is blue. In these conditions, any photo you take has a blue colour cast.
The easiest way to see a colour cast in your photo is to set white balance to daylight. If the colour of the light is blue, then it will come out blue in your photo.
If you use auto white balance the camera will warm the photo up to compensate for the blue colour cast of the light. That’s useful sometimes, but it’s not desirable if you want to create a moody image.
Blue light is atmospheric. That’s because some colours evoke an emotional response, and blue is one of them. It is a cold colour – it connotes cold, misery, bad weather, even depression.Orange light
Orange coloured light also occurs naturally. Light originating from the sun in the late afternoon, early evening or at sunset has an orange colour cast. So does light emitted by tungsten bulbs and burning flames.
Anything lit by these light sources will have a warm orange colour cast. Again, you will see it clearly if you set white balance to daylight.
Orange is another colour that evokes emotion. It is the colour of warmth and energy. It reminds us of things like the heat of summer or emotional warmth. Like blue, the psychological effect can be quite powerful.