Yes, you can add multiple palettes on your board.  Click on the " + " icon encircled on the bottom right of the current palette.

This will give you three options:

1. START FROM SCRATCH -  You can create a brand new palette strip under your previous strip from scratch i.e. by selecting, dragging and dropping colors.

2. LOAD FROM ANOTHER PALETTE - This option will redirect you to your saved palettes. Therefore, you can add a saved or shared palette strip.

3.  DUPLICATE THE STRIP ABOVE - As the name suggests this option will generate a copy of your previous palette and place it below that.