Solving the puzzles should feel like a step-by-step process, like climbing a ladder or putting together a jigsaw puzzle! Not like randomly trying to guess someone's password.
Try Grovyle's introductory tutorial again, they explain how to figure out simple steps like "Oh, there has to be a blue," "And there can't be any reds," "There's at least one green too." You never have to make a wrong guess! Think things through.