There is currently no way to set a style on a table row in the document generator. I recommend filing a feature request.
As for additional styling options, you can simply add CSS yourself in the 'Custom Styles' tab. The other tabs are only a couple of commonly used defaults.
I think you can find your answer here: Advanced tutorial
Look at this part: gridBody
The gridBody holds the different rows with our content from the forms. There are five tableRows we can change to our liking:
tableRow (standard Row style)
tableRowOdd
tableRowEven
tableRowSelected (when a Row is selected/active)
tableRowFocused (differs from Selected)
This gives us the freedom to adjust the different Rows with background colors.