hmm i think it was called confession, it's wayyy later in the novel. i'm not sure if it's the first time it was mentioned tho. let me send you a link:
https://sites.google.com/view/dd-dark-mode/dd-all-chapters/20-confession?authuser=0
Aside from this topic of his eyes, in chapter 22 when they were buying souvenirs, the director asked yeeheon to buy Morae and his Hyung gifts too, yeeheon told him that they already bought to much and the director replied "No,Bali" what did he mean by this and why did Yeehyeon felt burdened by his reply
I don't remember the exact details, but ihyeon refers to Juhan and Yuni as hyung and nuna too, so i think Yeehyeon thought liu was referring to yuni and juhan, and liu corrected to the hyung and nuna in bali.
The burden feeling was because Yeehyeon basically had no independence at all during that time, everything was paid for by Liu -- food, housing, first class flights, gifts... Yeehyeon basically borrowed money from Liu when he agreed to become an artist for Phantom -- you know how liu paid the uncle to get mr. lim get off their back, and paid for morae and yeehan to relocate to bali... yeehyeon, morae and yeehan see this act as debt they owe to Liu, so the more money liu spends on yeehyeon, the more yeehyeon felt burdened like he's never going to be independent, especially with how they lived then -- yeehyeon lives in liu's house, liu paid for food, first class flights, private driver 24/7 etc... yeehyeon didn't like that so many things involving his life involved liu too.
Hi
At the end of the side story "side by side" , when Yeehyeon was watering the garden and Kun approached him from the back, Yeehyeon suddenly apologized that he didn’t tell Kun his decision the way Kun did then after that he mentioned what the ring means to him and how he hopes it reaches Kun, I understood what he said but why did he suddenly talk about it especially when he wasn’t wearing it yet (I haven’t read the side stories after this one yet) and nothing in the narrative was talking about anything about the ring so was he talking about the ring Kun is wearing and that he loves it especially how he mentioned before that seeing Kun wearing it makes it feels like he’s HIS or what exactly, and how Kun after that thought that Yeehyeon was giving him more than their already great love, was he referring to the forgiveness he got from Yeehyeon, I read this part couple of times still don’t get their conversation and monologue here, if you could explain for me please

Why did his eyes change color?