Hiya! No worries - this was one of the first contraptions I made so it definitely could be made easier to operate. You can put a single Palette Storage contraption on any card and then add this to your deck script: (File > Properties > Script)
palette: cardName.widgets.paletteStorage
For the example above, I'm using 'cardName' and 'paletteStorage' as placeholder names for the card and contraption, respectively.
Then, in any other context (like the Listener, or a widget script) you can change the palette with the line:
palette.s: "nameOnList"