Hi RoniM
If I understood properly, I think that is how you can achieve this:
First, create the raw materials. Create one raw material for the colors and one raw material for sizes. They have to be variable raw materials in order to set all the colors and sizes you want:
Then create the parents, that is to say, each design. For each one, create a variable product with the colors and sizes attributes:
Create the variations:
We will use one variation as an example, but you have to do the same in all of them, and in the other product designs.
Open the 'blue-S' variation and go to the BOM section to put the raw materials: 'COLORS BOM - BLUE VARIATION' and 'SIZE BOM - S VARIATION':
Remember to enable the BOM Stock Control.
Hope this helps,
Best Regards,
Andrea.