Today, I got my hands on a Rubik's cube with text on it. It looks like this:

Now, I would love to know whether solving the right cube will also always correctly align the text on the cube or whether it's possible to solve the cube in a way that the colors match correctly but the text is misaligned.
Yes. But the total amount of misalignment (if I remember correctly; it's been a while since I played with a Rubik's cube) must be a multiple of $\pi$ radians. So if only one face has the center piece misaligned, it must be upside down. On the other hand it is possible to have two center pieces simultaneously off by quarter-turns. (This is similar to the fact that without taking the cube apart, you cannot change the orientation of an edge piece (as opposed to center piece or corner piece) while fixing everything else.)
(I don't actually have a group-theoretic proof for the fact though; this is just from experience.)
Edit: Henning Makholm provides a proof in the comments