Interesting VN, I have to note that there might have been a mistake in the dialogue for yellow girl who said that yellow girl was acting weird (which led me to think yellow girl was the one planning something lol), you probably meant to make her say something about purple girl. well done!
Edit: forgot to mention that the game crashes when you reach an ending, at least it did on web, can't say for the standalone ones, if its intentional then just ignore this.