When I upgraded a store from 126.96.36.199 → 188.8.131.52, suddenly the transactional emails (order confirmations) have slightly different formatting, even though none of those settings changed.
See the example below:
Old transactional email
P.S. I removed the item names & SKUs deliberately.
Note the line item color coding & light blue headers / grand total rows & text formatting of Grand Total
New transactional email
Note how the previously light blue column header row is now grey, Grand Total row is no longer light blue or formatted
Where can I begin to look into this?