Looks like variety blackdownense. I have two of them, and their new growths are the same color as those on your plant. Additionally, while some of my other speciosums do develop new growths that are somewhat red in color, the intensity is nowhere near as vibrant as those of the two blackdownense plants (and they all grow in the same area, so it's not a matter of the plants with more intense colored leaves getting any different levels of light than those that don't develop the same color intensity). The dark color will eventually change to the same standard green as the others.
Have a look at Gerry Walsh's website. He's got a lot of invaluable information on the different varieties of speciosum (including blackdownense and its distinctive new red-colored growths):
The Rock Lily Man
Your plant looks very healthy, by the way. Please post some pictures when it blooms for you.
Hybrid Mode
