COLORBLIND Trophy in Ghostbusters: Sanctum of Slime
Kill a Slime Abomination with the wrong weapon.
How to unlock COLORBLIND
The Slime Abominations are the larger enemies which throw goo trails at you. In order to unlock this trophy, you must be using the wrong weapon i.e. kill a yellow enemy with the red weapon. It's also worth noting that you must be awarded the kill so this is easiest to attempt in co-op as the CPU will more than likely use the correct weapons.
If they do use the correct weapons, wait until the enemies health is almost depleted and then switch to the wrong weapon and fire away.