I'm always looking for the just perfect watercolor palette. I bought this Koi Water Color Pocket Field sketch box several years ago. It came with 24 colors and a water brush. The colors it came with, I never did like, so I never used the set. So I decided to replace the watercolors with Yarka St. Petersburg watercolors from two different sets.
When I removed the Koi watercolors, the bottom of the box had uneven plastic, so I put a heavy duty piece of card board on the bottom to make the surface flat. By using the card board bottom, it allowed me to put 18 full pans and the water brush that came with set.
Now I have colors I would use in a very compact travel set.