Colour filters, known as gels (because they used to be made of gelatine), can be placed in front of any light to give it a colour. Technically, it doesn’t ‘give’ it any colour at all. A more accurate description would be to say that it filters out the colours not required. A pure blue filter, for example, would remove all the red and green from the spectrum, allowing us to see just blue.
Also, there are several gels which create certain effects. ‘Frost’ or ‘diffusion’ does exactly that – it diffuses the light. Sometimes it can be easier to hard focus all the profile lanterns, then use a frost gel to give the beams a soft edge. A variation of this is a ‘linear’ frost, which diffuses the beam in a particular direction; useful for spreading light evenly over the cyclorama, for example.
Most gel manufacturers produce a ‘swatch book’ which shows the full range of colours available. A commonly used manufacturer is Lee Filters. Their swatch book contains about 250 gels, so as you can see, the choice is immense.
See also Common Gel Sizes
The three primary colours of lighting are:– red, green and blue (RGB). (Note that these are different from the paint primary colours, which are red, yellow and blue). By using three lights – one red, one green and one blue – we can ‘mix’ the three colours to create many different colours. All three colours mixed together equally will make ‘white light’. This is called additive mixing.
Another method is subtractive mixing, whereby you would put more than one gel in front of the same lantern. In this case, the primary colours used are cyan, magenta and yellow (CMY). This is the most common way colours are 'made' in moving lights.
Colour is probably the most overtly artistic element of lighting design, but it also has some of the most scientific principles, which makes it very hard to summarise in such a brief text. Basically, colour can either be used naturalistically (i.e. creating sunlight or moonlight), or stylistically, in which case colour relates primarily to mood.
Colours can be grouped into two categories: - saturated or deep colours, and pastel or pale colours. As a rule, pastel colours or ‘tints’ are used in face lighting from the front, whereas deeper colours or ‘shades’ are used in side and back lighting, as well as for colour washes, special effects and lighting the cyclorama. The designer should not be afraid to treat ‘white’ (a lantern with no gel) as a colour also.
Colour is then defined by whether it is ‘warm’ or ‘cold’ or neutral. Warm colours include amber, pink, yellow and red. Pale pinks and ambers are the most commonly used for face lighting as they best compliment skin tones. Amber is also used for sunlight, as well as interior light. Red is a dominant saturated colour, meaning that it is the ‘strongest’ available colour; essential in the lighting palette, but mainly only used for colour mixing and special effects. Red, and warm colours in general, also makes objects feel ‘close’, as opposed to cold colours (see below) which make objects feel ‘distant’. This is called colour perspective.
Cold colours are primarily the blue range, of which there are probably more variations available than any other colour. Pale blues are used to compliment the pale warm colours in face lighting, and also to recreate natural daylight. Deeper blues can represent moonlight and night, and stylistically are the commonly used colour for suggesting a dark or ‘moody’ atmosphere. Green can be a neutral colour (see below), but depends if it is ‘yellow-green’ (warm) or ‘blue-green’ (cold). However, green is very unflattering to skin colour and is not often used except for effect or in colour washes.
Neutral colours are those which can appear either warm or cold depending on what other colours are used in conjunction with them. This can be useful when resources dictate that only one set of back lights are available, for example, and therefore a neutral colour would work with either warm or cold front light. The most commonly used neutral colour is lavender, but purple and green also border into this category;- again depending on the colour composition; for example, magenta is warm, whereas violet (blue-purple) is a cold colour.
An important factor to remember is that most theatre lamps are not ‘white’, but have a fairly warm/amber nature. This is especially true of lower wattage lamps, and when lights are dimmed to a low level. However, this inherent warmth can be partly overcome with the use of ‘colour correction’, which, in this case, compensate for the amber of the light and make it ‘whiter’ – or more blue in fact.
Without getting too scientific, colour can be measured in temperature, based on the relative red-ness or blue-ness of the light. A simple way to understand this is to compare the colour of a candle flame (very red; low colour-temperature) with that of the sky (very blue; high colour-temperature). Don’t get this ‘temperature’ confused with whether a colour appears ‘warm’ or ‘cold’, as it is actually inverse;- the candle has a low colour-temperature but is a ‘warm’ colour (amber), and the sky has a high colour-temperature but is ‘cold’ colour (blue)!
Colour Styles and Moods
Every colour suggests many moods. For example, red can represent anger, hate or danger, but can also represent happiness (i.e. warmth) or passion. Symbolically it can represent fire or blood, as well as the warmth of artificial light or the glow of a sunset.
Blue is the colour of the sky and can represent either day or night depending on the shades used. It can also represent sadness, or be harsh and oppressive.
Green can vary from expressing youth, fertility and nature, to symbolising jealousy or illness. It is quite a common trap to use green to represent trees and forests. However, even though the leaves are green doesn’t mean that the light coming through the tress will be green. Care should be taken and a real-life example sought. Having said that, green could be used to suggest a forest in a stylised setting. This is just one example of how different people may have different colour perceptions.
Violet can be mystical, sensuous or depressing. Pinks tend to mean happiness or comfort.
Yellow is like red; a powerful dominant colour, most obviously representing warmth, sunlight or liveliness, but can also be a very harsh colour if used at its most intense.
‘Open white’ at its most intense can represent purity, innocence or deity. Black, or no light, can also be used by the lighting designer just as effectively as using colour. Shadows can be sinister, scary or mysterious.
- Lee Filters
- Lightmoves colour filter reference has Lee filter selection, Lee & Rosco comparators