I can see a couple of issues:
1) Loss of red, more green now: Getting plants to grow red is much more difficult that many places on the internet will let you believe. Generally, plants go red based on a combination of: low nitrates, high phosphate, high iron, high light, high co2. You tank could be low on any one of those or high on the nitrates. If the plant is growing well, I doubt it's your light, but as a check you could let it grow up to the water's surface...if it starts to get really red, then maybe it's not getting enough light.
2)Roots growing from the stem. I think other people will have better answers, but I'll take a shot. This is the plant looking for food. Something is low, and I'd say that which is low is one of your macros: NPK. I'd check on your phosphates, see if they are low.
If your phophates are low, you'll probably kill two birds with one stone simply by upping them.