get a primary and secondary color name, estimated color name, and brightness from an rgb color and generate random colors

color_helper.js

// http://jsfiddle.net/eLbznqx0/

class Color {
  constructor(rgb) {
    this.rgb = rgb;
    this.colormap = {
      "110": "yellow",
      "101": "magenta",
      "011": "cyan",
      "100": "red",
      "010": "green",
      "001": "blue",
      "111": "white",
      "000": "black"
    };
  }
  dominant_color() {
    var max = Math.max(...this.rgb);
    var min = Math.min(...this.rgb);
    var range = max - min;
    var scaled = this.rgb.map(v => v - min);
    var scaled_pcts = this.rgb.map(v => (100 / range) * v);
    var scaled_ints = scaled_pcts.map(v => v > 60 ? 1 : 0);
    return this.colormap[scaled_ints.join('')];
  }
  secondary_color() {
    var pcts = this.rgb.map(v => (100 / 255) * v);
    var ints = pcts.map(v => v > 60 ? 1 : 0);
    return this.colormap[ints.join('')];
  }
  name() {
    var secondary_color = this.secondary_color();
    var dominant_color = this.dominant_color();
    if (secondary_color === dominant_color) return dominant_color;
    if (secondary_color === "white" && dominant_color === "black") return "gray";
    if (dominant_color === "white" && secondary_color === "black") return "gray";
    if ("white" === secondary_color) return "light-" + dominant_color;
    if ("white" === dominant_color) return "light-" + secondary_color;
    if ("black" === secondary_color) return "dark-" + dominant_color;
    if ("black" === dominant_color) return "dark-" + secondary_color;
    return dominant_color + "-" + secondary_color;
  }

  brightness() {
    var luma = 0.2126 * this.rgb[0] + 0.7152 * this.rgb[1] + 0.0722 * this.rgb[2];
    var brightness = (100 / 255) * luma;
    return Math.floor(brightness * 100) / 100;
  }
  static random() {
    return new Color([
      Math.floor(Math.random() * 255) + 1,
      Math.floor(Math.random() * 255) + 1,
      Math.floor(Math.random() * 255) + 1
    ]);
  }
}