There's another thread with some interesting information here:

https://www.houzz.com/discussions/3865436/help-narrowing-down-ficus-elastica-aka-rubber-tree-varieties

According to Central Florida Research and Education Center , " `Rubra' has dark, wine red leaves when grown in full sun. Much of the red color is lost as the plant grows under reduced light intensity. `Rubra' is also listed under the names `Burgundy' and `Abidjan'. "