I think you mentioned brown eyes being rare in LIT. Aside from being rare, are there any other reasons why the Twisted Wonderland residents like brown eyes? Do people in LIT's world associate eye colours with personality traits like how people in real life associate blood types with personality traits? Love your writing btw!
OOOOOOOOOH SOMEONE FINALLY ASKED ABOUT THIS!!!!!
So, yes, the rarity does play a lot into how they are perceived, but you are correct in that there are certain associations made with those with brown eyes similar to those personality trait lists for blood type, zodiac, etc. They would absolutely exist in LiT!twst.
To properly appreciate this, let me tell you the science I have made up as for why such fantastical eye color exist in the first place:
So, yes, it is because magic exists, but it's specifically because magic is a biological process in twst. Magic is within the body, and when used, creates blot as a byproduct, and you get it from there. Therefore, magic has to have it's own sort of "veins" (I liken them to the Meridians, if you're familiar with Chinese media) that travel along the body. And that magic results in come other biological changes to contend with it.
This, therefore, results in the different "effects" one might see when it comes to people using magic: sparks crackling from the body when someone gets emotional, or eyes lighting up when strong magic used.
As eyes are a central part in some magics (see: Jamil and the Leech twins), this means that eyes too have developed certain aspects as a result of magic. To contend with the backlight that happens when certain magics activate in the eyes, they've become more prismatic, resulting in more fantastical colors. Like what happens when you hold a clear crystal up to a beam of light and a rainbow appears on the other side.
Brown is not a color found naturally on a rainbow, and so, in twst biology, is the most biologically natural color. It is the least magically altered color, and has become recessive due to that, because it is less protected from magic. (Those with brown eyes in twst often develop eye troubles.)
Finally, the answer to your question, the association made with those with brown eyes: they are a person who is natural. Who is grounded in reality and is their truest self. Who doesn't put on airs or social masks. They are who they present they are.
Brown is beautiful because it is simply natural.