Tessellate

var foregroundColors = ["#30cb9f","#add8e8","#df91c5","#e24fa0","#263a93","#39b3e6"];

var triangleSize = intVariable("Triangle Size", 40, 160);
var colorCount = intVariable("Colours", 3, foregroundColors.length);

var half = triangleSize / 2;
var rowHeight = triangleSize / 2;
var palette = foregroundColors.slice(0, colorCount);

// Pick a colour that differs from the triangle to the left and the one above,
// so no two triangles sharing an edge ever match.
function pickColor(left, above){
  var color = left;
  while (color == left || color == above){
    color = palette[getRandomInt(0, palette.length - 1)];
  }
  return color;
}

var lastRow = [];

for (var row = 0; row * rowHeight < height; row++){
  var y = row * rowHeight;
  var thisRow = [];

  for (var k = 0; (k - 1) * half < width; k++){
    var x = (k - 1) * half;
    var color = pickColor(thisRow[k - 1], lastRow[k]);
    var points;

    if ((k + row) % 2 == 0){
      points = [x, y, x + triangleSize, y, x + half, y + rowHeight];
    } else {
      points = [x, y + rowHeight, x + triangleSize, y + rowHeight, x + half, y];
    }

    // A hairline stroke in the same colour hides anti-aliasing seams.
    s.polygon(points).attr({fill: color, stroke: color, strokeWidth: 1});
    thisRow.push(color);
  }

  lastRow = thisRow;
}