It's been moved to the Inspector's appearance tab. Alternating colors for the body and also for portal rows are now specified in the same part of the inspector.
Click the Body Part Level
Go to the Appearance tab of the inspector and select Body from the top drop down.
Then you select "Primary" or "Alternate" in the next drop down and select a fill color for each.
You also now have a new "active state" option for portal rows and List View Body parts that can be yet a third color to make it easier to see which record or portal row is the current row.
Thank you . . . I was able to find it quite easy with your description