plasma_five_color_gradient.js

const makeFiveColorGradient = (c1, c2, c3, c4, c5) => {
  const g = [];

  for (let i = 0; i < 64; i++) {
    const f = i / 64;
    g[i] = interpolate(c1, c2, f);
  }

  for (let i = 64; i < 128; i++) {
    const f = (i - 64) / 64;
    g[i] = interpolate(c2, c3, f);
  }

  for (let i = 128; i < 192; i++) {
    const f = (i - 128) / 64;
    g[i] = interpolate(c3, c4, f);
  }

  for (let i = 192; i < 256; i++) {
    const f = (i - 192) / 64;
    g[i] = interpolate(c4, c5, f);
  }

  return g;
};