Please enable direct control over colors of legend icons. I have for example a chart with a nice gradient effect: http://jsfiddle.net/6xZzf/ The same effect applied to legend icons doesn't look good. I would prefer to use plain colors in the legend, without the need to create a fake series for every chart element with gradient effect.
In addition, the legend for boxplot chart takes the colors from the item borders, which is quite illogical and there is no way to change the color easily: http://jsfiddle.net/t6pWJ/

Something like legendIconColor: '#rgb' for each data series would be sufficient