ansi 256

c256.js

var pad = function(n){
  return n < 10 ? "00" + n : n < 100 ? "0" + n : n;
}

var x = 6;

for(var i = 0;i < x;i++){
  var s = "";
  for(var c = 0;c < 240 / x;c++){
    var d = i + (c * x) + 16;
    s += ("\x1b[38;5;" + d + "m" + pad(d));
  }
  console.log(s);
  console.log("\x1b[39;49m");
}