I am not sure what else you analysis needs to show but the easiest way to handle this is to pivot your data.
(1) On you data source tab, select columns "Order Date" and "Ship Date"
(2) From the drop down menu select Pivot
This will create two new columns "Pivot Field Names" which shows if it is an order date or ship date, and "Pivot Field Values" which contain the date values. If you want you can rename these columns to something else.
(3) Change chart to use the "Pivot Field Names" and "Pivot Field Values" instead of Year([Order Date]) and Year[Ship Date])
(4) Change the color to "Pivot Field Names"
Again, you can change the field names to whatever you want.