Final color used for the gradient.
example:
chart.back.colorUntil=java.awt.Color.red;
chart.back.colorFrom=java.awt.Color.white;
chart.back.gradientType=FillStyle.GRADIENT_HORIZONTAL;
if true, RChart will calculate the max value of the scale using the preferred min/max values list
default value is true for Y axis and false for X axis.