I personally have painted a few of those particleboard-based stands, and I would honestly highly recommend it for a few reasons;
1) You can ensure the stand doesn't have the cheap, thin, and sometimes not wholly covered paint on the stand
2) You can add multiple coats, or even add a primer/more durable layer of paint so that if it gets wet from water, it doesn't peel or soak in and instead would use evaporate off (if dry enough).
3) You can let the tank match either the trim (if not black), or even match other things in the same room (since for whatever reason, the colors many stands come in are either black, a hard-to-match brown, or now slate grey).