Длина волны в RGB.
Взято из
https://www.johndcook.com/wavelength_to_RGB.html
const w = 640 // Длина волны
let red, green, blue;
if (w < 380 || w > 781) {
[red, gren, blue] = [0, 0, 0];
} else if (w < 440) {
[red, green, blue] = [(440 - w) / 60, 0, 1];
} else if (w < 490) {
[red, green, blue] = [0, (w - 440) / 50, 1];
} else if (w < 510) {
[red, green. blue] = [0, 1, (510 - w) / 20];
} else if (w < 580) {
[red, green, blue] = [(w - 510) / 70, 1, 0];
} else if (w < 645) {
[red, green, blue] = [1, (645 - w) / 65, 0];
} else {
[red, green, blue] = [1, 0, 0];
}
let factor;
if (w < 380 || w > 781) {
factor = 0;
} else if (w < 420) {
factor = 0.3 + 0.7 * (w - 380) / 40;
} else if (w < 701) {
factor = 1.0;
} else {
factor = 0.3 + 0.7 * (780 - w) / 80;
}
const gamma = 0.8;
const R = (red > 0 ? 255 * Math.pow(red * factor, gamma) : 0);
const G = (green > 0 ? 255 * Math.pow(green * factor, gamma) : 0);
const B = (blue > 0 ? 255 * Math.pow(blue * factor, gamma) : 0);
const color = `rgb(${R}, ${G}, ${B})`;
console.log(color); // rgb(255, 32.763138565028974, 0)
