I am in Montreal and Ludwigia super red doesn't exist here I have grown Ludiwigia Repens its nowhere close to that pinky red. Those super glowing red shots you see are usually someone who is shining purple/red light on their tank or who pumped up the saturation in photoshop not a realistic look to shoot for. I have gotten a nice saturated dark red but nothing like the picture above.
I don't know many of the plants yet but I would hazard a guess Ludiwigia Repens Super Red is one of the fastest red growers. I got them as green stems at about a foot tall. They converted to immersed, went red, and hit the top of the 20" high tank in just a few weeks. I've already replanted many cuttings. Mine have gotten redder since last I first posted but nothing like that deep red pic. The orange in these is beautiful too.