You can check your storefront to see what the customer sees.
If you don't setup the product and actually design it, it won't appear in your store.
I don't think the spreadshirt designer will allow you to actually put a non vector design on a colored t-shirt. It will show up as a choice, but I don't think you can actually put a design on it.
You can have vector graphics with up to 3 colors on dark shirts, just not digitally printed graphics on dark shirts.
If you don't setup the product and actually design it, it won't appear in your store.
I don't think the spreadshirt designer will allow you to actually put a non vector design on a colored t-shirt. It will show up as a choice, but I don't think you can actually put a design on it.
You can have vector graphics with up to 3 colors on dark shirts, just not digitally printed graphics on dark shirts.