Figure 1
An LED (a) consists of a chip, a conversion system and a multi-layer thin film that features ten layers. The latter focuses the emitted light spectrum into a \(\pm \,25^\circ\)-angle cone. The spectrum is composited of light rays (arrows) of different wavelengths. Such a spectrum is analytically associated4,5 with a point \(\mathbf {c}=\left( C_x, C_y \right)\) in the color space (b). The color point, roughly speaking, encodes the perceived color of a spectrum. The Euclidean distance between two color points (crosses) is denoted as the color point deviation d. In this work, one of these points is the so-called white (target) color point \(\left( \frac{1}{3}, \frac{1}{3} \right)\).
