First, we have Gens, Gens+, and GSavestate, using a max of 255 (FF):
Then, we have Gens/GS, Sonic CD PC, the wiki, SonED, and every other Sonic hacking tool, using a max of 224 (E0):
Note: this screenshot was taken in 256 color mode.
Then, we have Sonic & Knuckles Collection and the hidden bitmaps for Sonic CD PC, using a max of 238 (EE):
I restored this one by copying the palette already present in the file to the correct position.
So, which of these is "right"? None of them? All of them? Does it matter?