Drawing a 3D dataset (x,y,z) on 2D scatter plot.

The 3rd dimension (z) is presented as color on scatter plot. A color axis is used to guide user for the color.

An sample is posted at: http://forum.highcharts.com/highcharts-usage/how-to-plot-3d-data-on-2d-scatter-plot-with-smooth-color-t31107/