The ARC en CIEL series is created using the true spectrum of desaturated colors derived from rainbows.
Rainbows are meteorological phenomena produced through the reflection, refraction, and dispersion of light within water droplets, resulting in visible spectrums appearing in the sky as circular arcs. These phenomena occur when sunlight is positioned opposite the observer, allowing light to be optically separated and made perceptible. In rarer conditions, a similar effect appears through moonlight, producing what is known as a moonbow, in which the spectrum emerges with reduced chromatic intensity.