// there is probably a small issue with sign but the palette is very close

function convert8BitTo6Bit(eightBitValue) {

    return eightBitValue >> 2;

}

​

function convert6BitTo8Bit(sixBitValue) {

  return (sixBitValue << 2) | (sixBitValue >> 4);

}

​

function setup() {

  createCanvas(192, 192)

  background(0)

  noStroke()

​

  let pindex = 2

  for (let y = 192 - 12; y >= 0; y -= 12) {

    for (let x = 192 - 12; x >= 0; x -= 12) {

      let r = 127 - convert6BitTo8Bit(((pindex * 0x7f) & 0xffff)) >> 8

      let g = 127 - convert6BitTo8Bit(((pindex * 0x3f) & 0xffff)) >> 8

      let b = 127 - convert6BitTo8Bit(((pindex * 0x30) & 0xffff)) >> 8

      fill(r & 255, g & 255, b & 255)

      rect(x, y, 12, 12)

      /*

      let rh = r.toString(16);

      let gh = g.toString(16);

      let bh = b.toString(16);

      console.log(pindex, rh, gh, bh)

      */

      pindex += 1

    }

  }

}

​

function draw() {

​

}