How do I manage product options and variants for custom designs on Shopify?

[benjamin0077]

I need to understand how Shopify manage product option and variant :

For example if I have a personnalise product with print on demand so my product is always the same (same SKU)

The customer can custom 5 part of the product design printed by choosing one of 10 different colors for each part.(same 10 colors for each part )

Like that :
Part1 -ColorChoice : red, green, yellow, blue,…
Part2-ColorChoice: red, green, yellow, blue,…
…

I need to understand if :
Part1, … have to be a {{ product.option }} and for example the value red a {{ product_option.selected_value }} ?

Or

Part1, … have to be a {{ product.option }} and for example the value red a {{ variant.option1 }} ?

The goal is to have 2 distincts product in cart when customization is different and because the product is the same with just a different print, the same SKU for inventory.

Thanks !