This is a concise guide on how to enable "make to order" at the variant level, rather than the product level.
Initially, you have the option to enable "make to order" for the entire product. However, there are times when you specifically want to enable it only for certain colors.
To accomplish this, follow these steps: Go to the product's details, then navigate to the variants section. Select the color for which you wish to modify the setting. Next, choose the desired number of items and update the data. Locate the "make to order" option (B2B or B2C), and override the product setting to enable it.
Once this setting is enabled, you can now sell more units of that specific product than what you currently have in stock.
Conversely, if you want the product to be "make to order," but one variant should not follow this rule, you can still use the same guide. However, when changing the "make to order" setting, select "no" instead of "yes" for the variant that shouldn't be make to order