Hello Karinth :) Thanks you !
Regarding your questions :
1/ itch.io and Unity are 2 separate bundles indeed. It is way better to use the Unity bundle if you are using this engine, mostly because of the autotile integration, tilepalettes and the all-in-one assets included. Unfortunately I have run out of download keys for the Unity package (12 a year only), but I can send you some cash back if you mail me your Paypal (my mail is pixelart[dot]asset[at]gmail[dot]com)
2/ If I'm not mistaken, the color palette is present in most of the global atlas.png files (one for each package). Let me know if you find it (it's right next to each title section) :
peace