Eiffel Tower Black Tower Elderberry Growth - October 2024

In the middle of last Summer (July 2023), I planted a pair of dark foliage shrubs - Eiffel Tower Black Tower Elderberries - along the fenceline about mid-way back.  Looking back at them when they went in, the were short and compact.   Now, 15 months later, both of the shrubs are doing fine - putting on some vertical growth and doing their 'tower' thing.  They're not...however...black.  See below:

This season, they're up over the top of the fence (you can see in the background), so they've bulked-up height-wise.  I cut these back to about 2' off the ground this Spring and I'll do that again.  

According to the description, they're supposed to 'age to black', so perhaps that's still coming?  (I doubt it).