Support for extended palette
In the new versions of pico-8 there are some secret POKEs that you can do to access an alternate darker/warmer/autumny 16 color palette. You can only have 16 colors onscreen per frame but you can mix and match from both palettes as you please.

You poke the regular color palette registers in the draw state (0x5F10-0x5F1F) as normal but add 128.
You can also do this by using pal(color_to_replace,new_color+128,1)
POKEing 0x5F2E with 1 will help with testing this as it prevents the colors from resetting after the program ends.


![extpal p8](https://user-images.githubusercontent.com/20967774/66089773-8c0cdc00-e578-11e9-85ca-b5142e59ed14.png)


Here's a link to the extended colors: https://lospec.com/palette-list/pico-8-secret-palette
They look pretty accurate although I haven't checked if they're exact 