Amazon Error 90057: The variation-theme field contains an invalid value
- visit Amazon -> Settings -> Advanced
- find the box "Map Variation Attributes"
- on the left side, select "Shoe Size" as WooCommerce attribute
- on the right side, select “Size” as Amazon attribute
- click Save Settings
What is the difference between the variation theme "color" and "ColorName"?
Some feed templates allow different versions of the same attribute, like "color" and "ColorName" or "size" and "SizeName". To our knowledge, these versions are treated equally. Even Amazon Seller Support wasn't able to shed any light on why those different versions exist (even though we got multiple answers which all turned out to be wrong), so it doesn't matter which one you use.