Inventory: Kindly develop multiple Size and corresponding stock mapping adding option for single stock

Background: In my inventory, I’ve Shirt which is Red color.
For example: <Red color shirt> - Item Name

<Size 1-2> - <No of pics 20>

<Size 2-3> - <No of pics 24>

<Size 4-5> - <No of pics 10>

If want to add this I need create many Items for that same color. Which more time taking and lot of data will be there.

To reduce this effort kindly add Item to support multiple Sizes and no.of available pics.
In the invoice section provide a drop-down to select the Size for the item.