Monochromes' existence is kind of hard to explain. They are visible and animate but technically "not real".
Think of them as a broken fragment of someone's memory or a small piece of someone's existence. They are only a piece; incomplete.
Because they are "not real" their appearance is only a manifestation of their desired looks, hence their looks / clothing may vary a lot from each other.
Many Monochromes can belong to the same person.
Often, they are unaware of what type they are and would have to figure it out by themselves.
After they regain their colors, some disappears and some stays around by their will. The "will" has to be a strong desire motivated by a valid reason.
MONOCHROME TYPES
▶ Nostalgic - They are Monochromes of someone who passed away. They cling onto an unfinished memory and their goal is to complete it. To regain their color, they may have to attend to unfinished business. (ie. fulfilling a wish, fulfilling a promise, finding a lost item... etc.)
▶ Reminiscent - They are Monochromes of someone who passed away. They cling onto a happy memory, unable to let go. To regain their color, they may have to find other Reminiscent Monochromes to remember and relive a memory.
▶ Grievance - They are Monochromes of someone really depressed or has passed away. They are the angry and hateful part of a person. To regain their color, they obviously have to clear up a misunderstanding or succeed in their torture or revenge.
▶ Malicious - They are Monochromes of someone really depressed or has passed away. Different from the Grievance Monochromes, instead of seeking revenge, they purposely cause misfortune upon innocent people. How they regain their color is unknown but it may include meeting someone or seeing something that will change their mind. Though that may be hard.
▶ Reviving - They are Monochromes of someone who is missing their memory or parts of their memory due to old age or an accident. They are in search of missing pieces. Similar to the Reminiscent Monochromes, to regain their color, they would have to find other Revive Monochromes to complete a memory.
▶ Drowsed - They are Monochromes of someone in a coma. They have no set purpose and wonders around till it's time for them to disappear (when the person dies or wakes up.) To regain their color, they may have to discover the will to live on or learn to let go.
▶ Pure - They are Monochromes of someone who has lost their sanity. They represent the only sane and good part of the person left. To regain their color, they may have to grow stronger and overcome the insanity.
▶ Unpure - They are Monochromes of someone who has lost their sanity. They represent the insane / negative part of the person. To regain their color, they will have to come across a pure monochrome.
▶ Bleached - They are Monochromes of no specific origin. They are like empty shells with no purpose. They are the most mysterious type of Monochromes because they wander around, lost, yet have no goal or purpose so they stay lost. They rarely regain their color. How they regain their color is unknown.