Their names are Hope Phil and Hope Liz. (for this species, the last names come first) They're a strange species that feeds off of certain emotions. Each individual feeds off of a specific emotion to get the energy they need to survive. The species nearly went extinct because the emotions they fed off of were too specific to find a reliable source for. The only two left are Hope Phil and Hope Liz. Phil feeds off of positivity and Liz feeds off of negativity. Liz can use a little bit of energy to turn someone into what's basically a negativity generator. When this happens, the person's colors will fade and turn into shades of grey and black. They won't be able to feel any positive emotions or think any positive thoughts. Liz will use this person to fuel herself. Phil can do practically the same thing but with positivity. When he uses a little energy to tap someone, their colors will turn more vibrant, and they will only be able to feel and think positively. Bonus fact: Phil hates it when people call him "Phil Cipher".
Feel free to ask questions. I'm not the best at explaining things.