Awesome looking tank! Maybe add some rotala macrandra to give some more contrasting colors? For instance the aromatica on the right could be replaced with a very bloodred plant. Once your plants grow and you can make the bushes thicker, though, this tank is going to be phenomenal regardless of color (with some good shaping).
The problem is I have never been able to achieve deep red coloration... I'm not sure if it's my lights or anything else. Ludwigia rubin can be blood red, but it's not in my tank...
I also have trouble achieving dense growth, because normally the bottom leaves just die off, is this because of slow growth?