I'm new to any kind of lighting, so sorry if this is a dumb question.

I'm looking for a small, portable wash that can smoothly fade through a wide color pallet VERY slowly - as in taking several minutes to fade from one color to the next. This is for a very simple and portable setup, so it needs to be a built-in function that doesn't require an external controller.

It doesn't have to be super-powerful. This is for my 3-piece and we just play small rooms. The idea is to get a few of these and have them wash up at us set to very slow but asynchronous cycles - so the colors are cycling very slowly but not in sync with each other (color or time-wise).

FWIW, I tried two cheap ones from Amazon

JLPOW COB Par Lights - this is probably bright enough and has a nice wash angle, but the slowest fade cycle is still too fast. Probably about 10 seconds max between colors.

YeeSite 36 LED Par Lights - the slowest cycle is about 30 seconds. Ideally it would be longer, but I could work wit this. But the beam is too focused. (And ideally the color transition would be smoother, but again that's workable.)

I'm finding that online manual don't seem to specify the max fade length, so any help is appreciated! (And sorry if this has been covered here and I missed it - I did try searching but didn't see anything on this specific topic.)

Don't know if you got anything yet, but i just got the Chauvet DJ Colorstrip, the 38" and it can do what you explained and its perfect for a 3 piece band and small rooms.
It cost about $170 and i bought an IRC remote for $26 to control it.

Chekc it out in action - https://www.youtube.com/watch?v=n3SnA55Nc6o