Hi!

I watched a tutorial the other day which showed there is an alternate pallet in the pico 8, but it wasn't as straight forward to use as just using the editor. Are there any plans on adding the second pallet to the editor? And in extent, may be the possibility to modify the pallet via the gui?

You can only define custom palette with code (with 'pal(c1, c2, 1)'). There are some tools on this forum and github to make it easier to define a palette, but in the end they all give you lines of code.

Add 'poke(0x5f2e, 1)' to your code and your custom palette will stay active when going from game to editor.