A character I'd like to try out~

Once upon a time, the world was a place devoid of colour. And so it remained, until the Spirit of Creation made four simple shapes using red, blue, green and yellow. These shapes became the Sun, Sea, Land and Wind. Afterwards, the Spirit of Creation made two other shapes. The first was Mankind, possessed of a free mind. The second were Sketches, possessed of a free body. Some humans were able to create Sketches and Sketches made new colours. These humans were called Muses.
 
The world was filled with colour and the humans were happy. One day however, a king was born among the Muses. This king, in order to obtain more colours, enslaved the Sketches. But in doing so, the Muse king deeply saddened the Sketch King. The Sketch King pleaded with the Spirit of Creation,
 
“Spirit…Please, do not let those whose hearts are impure continue to create Sketches. If you grant this wish, I will return to you both my body and all the colours under my control.”
 
The spirit granted the wish, and from then on, only those who possessed a pure heart were able to create Sketches. The Sketches were freed from their enslavement. But…the cost was heavy. The Sketches lost their king and many of the world’s colours disappeared. Frustrated, the Muse king looked to control the Spirit of Creation with the Sketches he still had. In doing so, he drove the Spirit into a deep slumber and brought misery upon the world.
 
When the Muse king and his followers tried to use the Spirit to regain their Sketch abilities, it went out of control. Their Sketches warped and drained of colour, becoming colourless monstrosities. These fearsome monsters became known as Scrawls. Unlike their counterparts, Scrawls consumed colour, draining the life of everything around them. Driven mad with power, the Muse king tried to use his new army of Scrawls to take over the land. With the last of its power, the Spirit of Creation sealed away the Muse king deep under the earth, before vanishing from the world.
 
The other humans were enraged and terrified. They hunted down the Muse king’s followers and their Scrawls, branding them Witches. Once the last of them had been driven into hiding in the wilds, the humans turned their suspicion and fear onto the pure-hearted Muses still remaining. Afraid they would go mad and turn into Witches, the humans attempted to purge the pure-hearted Muses from their towns. They were ostracized; banished from living in human communities and stigmatized. And so, the pure-hearted Muses began to die out.
 
The humans did not realize their mistake until many years later. The colour in the world began to dwindle, whole forests turning to nothing but grey wasteland. Without Muses to create Sketches, there could be no new colours. Without new colours, the world would die. The human kings saw this and devised a plan. They sent out their soldiers to find all of the Muses across the land, forcing them into servitude. Still, it was not enough. Without the Spirit of Creation, the powers of the Muses were weak and they would corrupt easily, transforming into terrifying Witches. And so, the colour of the world continued to dwindle and fade.
~--------------------------~

Basically, the seaside town Nia lives in has an abnormally stable colour level. Your character would be a soldier/soldier-in-training, or maybe a researcher/grad student studying Sketches and Muses. Basically just someone who would be suspicious enough of Nia to stick around the seaside town. For the first bit, I was thinking maybe your character would investigate, questioning the townspeople or maybe trying to follow Nia around. While following Nia one night down at the beach, he gets attacked by a Scrawl and blacks out. When he wakes up, he is in the medical clinic and relatively unharmed. Long story short, he basically hangs out with Nia for the next couple days while he recovers, and begins to notice some weird things about the town whenever he’s with her. Eventually, this culminates in more Scrawl attacks, after which Nia agrees to accompany your character back to the capitol or whatever to petition for some soldiers to guard the town. Along the way, they get caught up in all kinds of trouble and it becomes blatantly obvious that lots of bad things are going down; like “world is ending” kind of bad things. Or at least that’s the rough idea, lol.
The setting is pretty much modern, though the level of technology varies wildly depending on where people live. Additionally, there are random swathes of land that are quite literally just grey wastelands filled with dead grass and dead trees.
Colour is treated as a sort of luxury, and can be exchanged/sold in the form of colour gems (basically just very shiny rocks that are super vibrant in terms of colour). Rich people have colourful homes and clothing, while the less fortunate tend to be more monochromatic in terms of the things they have. Colour is also what sustains life, so it can also be used for nourishment/medicine. For instance, a common disease is monochromatia, which is characterized by a person having “low colour”, and it can be treated by crushing colour gems into the afflicted individual’s food.