Simple row color by lookup field

smithme 

Seems you are using wrong JSON schema. You should use 

https://developer.microsoft.com/json-schemas/sp/view-formatting.schema.json.

And not this:

https://developer.microsoft.com/json-schemas/sp/v2/row-formatting.schema.json

For view formatting, refer below Microsoft official documentation:

View formatting - Apply conditional classes on rows

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