A proposal for the definition of colored light sources in lighting CAD

In the last ten years, the introduction of LED lighting sources has brought elements of innovation to interior lighting design. Besides the new tunable white LED source, light is no longer exclusively white; indeed, colored lighting has wholly entered the design practice thanks to the positive effects on people's health and mood. Unfortunately, these elements of innovation cannot be computed correctly in commercial Lighting CADs. These are based on the assumption that light is only white or defined in terms of RGB triplets in the relative color space of the computer graphics, which does not have a physically correct relationship with the actual spectral power distribution (SPD) of light sources. In this paper, the attention is focused on describing the light sources for practical lighting design that also consider the SPD. The focus is on information available to lighting designers who cannot have a laboratory to measure light sources and luminaires. This information is nowadays available in online datasheets from luminaires and light sources manufacturers. Following this idea, a set of functions is proposed to be easily implemented in Lighting CAD software to improve light sources' color management.