I appreciate you reaching out about adding color & size variants in QuickBooks Online (QBO), Grizzly.
The option value refers to the color, variant, etc., and adding a size and color or option values to a product during batch import is unavailable.
Alternatively, you can input the color and size details in the Description column or the Product/Service name in your Excel file to include them in your batch import.
Then, refer to this article for additional details on importing a batch of your products and services: Import products and services into QuickBooks Online.
For future reference, you may want to check these articles to help you make changes to your products and services :
Let us know if you have other concerns with managing the product and service. We're here to help you in any way we can.