I’ve played around with both tubes and dry “blocks”. For best of both worlds, you can get palettes that come in a box with removable sections that can be filled with whatever color paint. I filled these with paint from tubes, and by keeping the box closed it will mostly retain moisture of the paint while storing. If left long enough they will dry out, but being water colors, I just mist them with water and they work again.

The one I have is basically like this https://a.co/d/j4TrTo6 .

Also - you can get brushes that hold water! It’s basically a brush with a water chamber, and you squeeze it to put more water into the bristles. Makes it easy to travel, but for me it’s far less messy and keeps the colors cleaner.