I agree with you on the colors
the game feels too grayish. not only the gray-white colors from the inn and rocks you mentioned, but all the colors from the environment itself
the characters colors are fine, but everything else (water, grass, inside building objects, the buldings itself) feels too desaturated. a game with that cute paper art style should be probably more colourful.
but be careful with that: too much saturation is a bad thing too if not done right (specially on simplistic styles, which is your game's case)
anyway, the game itself feels very pacific/calm and fun, which is great for these sort of games
give it a comfy soundtrack and you are set for good
looks very promising