Its probably completely personal preference but I found the variations of colors a little "in my face".. It didn't seem obvious to my brain which color was old and which was new (normally it was a mixture of green, cyan, oranges and purples!)

I changed the code slightly in my instance to use just a linear scaling of a single color (in this case green), the darker the green the older the commit. (adjusted slightly to keep it away from being bright green)

  var v_min = 0.0;
  var v_max = 1.00;
  var v = v_min + ((v_max - v_min) * epoch_value);
  row.info.style.background = getLinearGreen(v);
}

function getLinearGreen(v) {
  var r, g, b;

  r = Math.round(v*240);
  g = 240;
  b = Math.round(v*240);

  return 'rgb(' + r + ', ' + g + ', ' + b + ')';
}

I'm not a graphic artist and not gifted with artist talents! so feel free to ignore me..