Graphics Color questions

Well,

try this one for the moment:

  let ScreenWidth  = g.getWidth(),  PatchWidth  = ScreenWidth/6;
  let ScreenHeight = g.getHeight(), PatchHeight = ScreenHeight/6;

  g.clear();

  for (let i = 0; i < 27; i++) {
    let x = (i % 6)         * PatchWidth;
    let y = Math.floor(i/6) * PatchHeight;

    let R = i % 3;
    let G = Math.floor(i/3) % 3;
    let B = Math.floor(i/9);

    g.setColor(R/2,G/2,B/2);
    g.fillRect(x,y, x+PatchWidth-1,y+PatchHeight-1);
  }

  g.setFont12x20();
  
  Bangle.on('touch', function (Button,Position) {
    let x = Math.floor(Position.x / PatchWidth);
    let y = Math.floor(Position.y / PatchHeight);
    
    let i = y*6 + x;
    if (i >= 27) { return; }

    let R = i % 3;
    let G = Math.floor(i/3) % 3;
    let B = Math.floor(i/9);

    let HexValues = ['00','80','FF'];
    
    g.setColor(1,1,1);
    g.fillRect(3*PatchWidth,4*PatchHeight, ScreenWidth,ScreenHeight);
    
    g.setColor(0,0,0);
    g.drawString(
      '#' + HexValues[R] + HexValues[G] + HexValues[B],
      3*PatchWidth,4*PatchHeight+6
    );
  });

I'll make a "real" application out of it as soon as I find the time (it's Christmas right now, you know...time for the family)