Aseprite script that converts the current palette into a 12-bit (4096 colour) palette, i.e. 4-bits per channel.
To install in Aseprite, go to File -> Scripts -> Open scripts folder
Then drop the script into that folder and restart Aseprite. You might also want to assign a hotkey to the script via Edit -> Keyboard Shortcuts.
It's also useful for things like creating gradients. Just create a gradient in the normal way, then run the script, and each colour in the palette will be nudged into the closest CX16 colour.
Corrected the palette conversion to use the colours from the emulator, which are slightly brighter.