Photography is all about light, but very often we neglect the colour of that light. It's all very well using AWB or making our images neutral so the colours are "accurate" but in the end it's an emotional response we are looking for, and the colour of the light used can really add a new dimension to our images. Because I shoot in JPEG I do pay attention to the WB setting and routinely use Daylight rather than AWB. The reason is that I don't want the camera to try and take the colour bias out of a scene where the colour of the light is paramount. For example, I don't want a red sunset diminished as the camera tries to measure an overall neutral grey. When it's cloudy I use Cloudy to warm the image, when it's very overcast the shadows can be very blue/purple, so I use Shade. For good measure, there's nothing wrong with using the wrong colour balance if a special effect is required.
But let's go a step further today and have a look at some images that use the actual colour of the light source as a major part of the effect, rather than just the colour of the subject matter. Colour balance can be thrown out of the window and we are here just looking for the colours we want, be they accurate or not.
The ballet - all about dramatic colour
Night Frog
Frankie Valli & Robby Robinson - stage lighting
Concentration, and wonderful ambient lighting from the tablet
Kyle, macabre green
A tinge of red light from a subtle sunset
Red Light Boogie
The Blue Room, a stage setting
Kelly by Candlelight
Mevagissey at Night
The Vampire, inspired by Night Vision Most Haunted
Cassie lit with red gels
Andrea by Candlelight
Sunset
Apocalypse
Developing a print under red light