You could''ve done that yourself.
I used the MD palette (or rather what emulators use). The RGB values used are 0, 34, 68, 102, 136, 170, 204, 238.
Edit: Tried "posterize" now and it both gives wrong values and adds one more value to the palette, so it would've been useless.
64 to 50/58 colors (8 colors overlapping) - Sub palettes considerate mockup (background=30c, sprites+hud=28c).
Super Metroid SNES (113 colors) to MD - The liquid can be done with mid frame palette switching to show more colors at once, like in the Sonic games, though it might not look exactly the same.
52 colors (or 73 with the liquid effect)/43 or 66c (15 or 39 for bg, 30 for sprites+hud).