The snaps are deliberately placed at slight angles, since most babies are more narrow at the waist than the hips / thighs. (themamaknows.com)
I actually started to notice the colour shift, in green mainly, at very slight angles. (sammobile.com)
I started using my putty knife, laying it at the loose end at a very slight angle from the horizontal and then gently hit the end with a hammer just to get under it. (revolutionaryredesigns.com)