jqPlot - How to change opacity or z-index of canvasOverlay?

Question

I would like to show 3 color zones on my graph on the background according to y axis value, as I understand, I cannot control the background color by different colors.

Answer 1

A much better solution is to use Canvas rectangle object without any hacking http://services.mbi.ucla.edu/jqplot/examples/draw-rectangles.html

$(document).ready(function(){
  var plot1 = $.jqplot ('chart1', [[30,-10,90,20,50,130,80,120,50]], {
      canvasOverlay: {
        show: true,
        objects: [
          { rectangle: { ymax: 0, xminOffset: "0px", xmaxOffset: "0px", yminOffset: "0px", ymaxOffset: "0px",
                    color: "rgba(0, 0, 200, 0.3)", showTooltip: true, tooltipFormatString: "Too Cold" } },
          { rectangle: { ymin: 100, xminOffset: "0px", xmaxOffset: "0px", yminOffset: "0px", ymaxOffset: "0px",
                    color: "rgba(200, 0, 0, 0.3)", showTooltip: true, tooltipFormatString: "Too Warm" } }
        ]
      } 
  });
});