We have the same request as ChristyN here at our office.  We are using Desktop Pro 2020 and QB was printing alternating color rows for me up until a week ago.  I believe I must have unintentionally caused a setting to be changed as I was printing one day and now it is not print the alternating colors anymore.  Could it be that this feature is still available in Desktop Pro 2020 but that the toggle or check box has been moved?  

Thanks,

BradM