I've been hanging on to this one for awhile. I wanted to update my main story before I posted any more one shots.
My friend wrote everything from Flowey because I couldn't figure out how to wrap it up. I don't own Undertale or it's characters.
Chara loved to tell stories, and Asriel loved to listen.
Chara's stories were all colors and light. They spoke of the sun and it's yellow rays, of the explosion of oranges and reds in the fall, the deep blue of a sky about to go to sleep for the night. Colors, Asriel learned, were something his human friend adored.
Humans, on the other hand... When Chara would tell those stories, their face would go dark and their hands would tighten into fists. Their voice would become more monotone and less reverent, and even their eyes seemed to go dull, void of any of the colors they so fiercely admired.
Asriel noticed this, and decided that it was up to him to prevent Chara's colors from ever going dull again. He drew pictures and told his own made-up stories, took Chara to see the echo flowers and stars in Waterfall, and did everything he could to keep Chara's mind firmly away from the cruelty of their own species. And it worked. For a time, at least.
Chara's favorite color was yellow. They never explicitly said this, but they didn't have to. Asriel could tell by the way their eyes lit up and their hands gestured wildly when talking about the flowers from their village or of the sun, by the way the yellow crayon was always the first one Chara would grab, how they'd even painstakingly knit a yellow sweater for Asgore (the words "Mr. Dad Guy" emblazoned on the front had made Asriel's father, the King, excuse himself with tears in his eyes.)
Asriel had never had a favorite color, but he decided that if yellow was good enough to be Chara's favorite color, then it was good enough to be his, too.
Flowey refuses to have a favorite color.
If anything he will have an order of least favorites; they go from tolerates to despises. It shouldn't surprise anyone (not that anyone has asked him what his favorite color is). No, Flowey thinks it's completely rational on his part.
So what if he flinches a little when he accidentally catches his reflection in the pools and puddles (he may or may not have grown an avoidance of any reflexive surface). If he had it his way the underground would lose the so called colors it had. No more blues that were supposed to be a deep color to show the sky going to sleep, a banishment of any oranges and reds that were supposed to take him with when they exploded.
Yellow is to not be acknowledged as a color. How could it when the scale only goes from tolerate to despise? No, yellow doesn't exist. Because if it did then it would be in its own category.
He can't despise it (because it helps him remember) and he just cannot tolerate it (because it makes him scared).
Chara in my mind is not evil. They're just a kid who made some mistakes but still loved their brother and their family. Feel free to fight me on that.