I finally got the chance to play around with one of these. It does warm white, around 2700K, very well. As Dan said, it adds in red or blue LEDs to make the color temperature warmer or cooler. To my eyes, it does not do this nearly as well as the Hue Lightstrip Plus. The warmest it can go doesn't look much warmer than the "default" warm to me, or at least the reddish/orange-ish hue is much weaker than I'd expect. Similar with the cools. They also seem to be brightest at 2700K and less so at lower or higher temps (for comparison, I think Hue is brightest around 4000K, which I also find to be a nice neutral white that isn't too cool but is better than a warm white for work areas like a kitchen).
So if you're hoping to use one of these to emulate Hue's default "Relax" scene (something like a bit under 2250K at about half brightness), you'll be disappointed--it will still be too "cool" of a warm white. I was able to get something similar enough by switching to color mode and finding a yellow-orange hue, so they're probably capable of doing this, as long as you don't want it too bright (which here I don't). Many colors aren't super bright or vivid, but it's not much different from the first couple generations of Hue bulbs there (the third and newer have a wide gamut and do most quite well, albeit not all at equal brightness).
That being said, they do cost significantly less. I've also played around with a bulb (the Plus) and noticed the same--brightest around 2700K, with the cools and and (especially) the warms not getting as cool or warm as intensely as I see with Hue. If you're happy with their bulbs, you'll likely be happy with the strip, too. I'm just much happier with how Hue handles shades of white.