Opacity

In several of the controls we can control the color via an expression, but the opacity uses a slider so it cannot be controlled by expression. We would like to either be able to use the ARGB function in the color expression or use a separate expression if necessary to control the opacity of pie slices, bars, lines, fields, columns, etc.  This can be very useful to either highlight (or "gray out") specific items on/in the chart / table / etc. It can also be quite helpful in a Heat Map. We previously used the ARGB function for this purpose frequently within QlikView.