Love the art style: the use of distinct colors makes the puzzles very understandable and the minimalist style does not distract from the task at hand. Managed to beat the game without any hassle! Concepts are introduced clearly and the difficulty curve feels really smooth, even though it stagnates quite early given the relatively small level size. I feel like it would be more intuitive if guards would let you through with a pass in their color, not the other way around though. Also it feels odd, that a pass is lost, if you pick up another one. Why not swap them out? Lastly: If you restart the first level, the game does not reset the passses and doors. In later levels it works as intended however. :)
PS: Our games are build around the same basic idea: in my case there are keys instead of passes and you have to use them to unlock blocks instead of convincing guards - give it a try! :) As people who enjoyed my game, will definitely enjoy yours as well, I updated my game's page with a link to yours.
My game: https://njamster.itch.io/wonkey (playable in browser)