You can interactively change the color of the box plots, by right clicking on the chart and selecting "Customize"

Programmatically the script below was what the graph builder generated after I changed the color of the boxes
Graph Builder(
	Show Control Panel( 0 ),
	Variables( X( :age ), Y( :height ), Overlay( :null ) ),
	Elements( Box Plot( X, Y, Legend( 6 ), Box Style( "Solid" ) ) ),
	Column Switcher( :null, {:age 2, :null} ),
	SendToReport(
		Dispatch(
			{},
			"Graph Builder",
			FrameBox,
			{DispatchSeg(
				Box Plot Seg( "Box Plot (12)" ),
				{Line Color( "Medium Dark Red" ), Fill Color( "Medium Dark Red" ),
				Fill( 0 )}
			), DispatchSeg(
				Box Plot Seg( "Box Plot (13)" ),
				{Line Color( "Medium Dark Green" ),
				Fill Color( "Medium Dark Green" ), Fill( 0 )}
			), DispatchSeg(
				Box Plot Seg( "Box Plot (14)" ),
				{Line Color( "Medium Dark Blue" ), Fill Color( "Medium Dark Blue" ),
				Fill( 0 )}
			), DispatchSeg(
				Box Plot Seg( "Box Plot (15)" ),
				{Line Color( "Magenta" ), Fill Color( "Magenta" ), Fill( 0 )}
			), DispatchSeg(
				Box Plot Seg( "Box Plot (16)" ),
				{Line Color( "Gray" ), Fill Color( "Gray" ), Fill( 0 )}
			), DispatchSeg(
				Box Plot Seg( "Box Plot (17)" ),
				{Line Color( "Medium Light Orange" ),
				Fill Color( "Medium Light Orange" ), Fill( 0 )}
			)}
		)
	)
);
					
				
			
			
				
	Jim