When pretty colors start being more than just pretty colors, it may be time for you to get your head examined. It might not be anything but, you know, better to be safe than insane.
I don't give books star ratings; I give them bite ratings. This is a bite. A book can get up to five of these evil-looking chompers, including half bites.
You can attribute your own wording to the ratings. Five's the best, three's decent, one and under isn't worth the gas to go to the library. I'll leave it to you to fill in the blanks.