Colour mixing is the process of combining light components to create a resulting colour. LED fixtures usually mix emitter outputs additively. Physical colour filters work subtractively by transmitting some wavelengths more readily than others.
Choosing a control mode
CCT mode specifies a white-light target, often with a separate tint adjustment. HSI sets hue, saturation and intensity. RGB controls specify colour-component levels, while xy specifies a chromaticity coordinate. The exact interpretation and available controls depend on the fixture.
Practical example
To repeat a backdrop colour across several setups, record the fixture model, colour mode, values, intensity and any modifiers. If changing brands, an xy target can be a useful common reference, but check that both fixtures can reach it and compare their actual camera result.
A colour match has limits
Two mixtures can have similar chromaticity while using different spectra. They may match on a white card and separate on coloured objects or under a different camera. Output also varies with the mix, so confirm exposure after choosing the colour rather than assuming a white-mode lux figure still applies.
Equipment examples
The Aputure Nova P600c and ARRI Orbiter provide examples of different colour engines offering several ways to specify a colour.
Related terms
RGBWW · RGBACL · CCT (Correlated Colour Temperature) · SSI (Spectral Similarity Index)
References
Aputure: colour modes explained · Aputure: individual-emitter profiles