Spoilers for The Ragpicker King
Conor's complicated relationship with the colour red.
°we find out early on (from the first pages of Sword Catcher) that Conor doesn't like red hair and it was a deal breaker for him in an arranged match.
° We find out that he paid Silla to stay with him while he rested because the colour of her hair closely resembled Lin's (and he called her by Lin's name), a weird occurrence to Kel since Conor has never expressed any interest in Silla and has said to find red hair unattractive.
°When they're kissing at the ball Conor takes down the clasps from Lin's hair so they could fall down and he breathes her in. He does the same later on when he's trying to comfort her.
°There's a line somewhere towards the end of Ragpicker King where Kel thinks that the cape Conor is wearing flows behind him as he leaves, and it reminds him of Lin's hair. It is a moment of tension for Conor who just got rejected by Lin, denying him even a bit of happiness, and he wears her colour on him, as a way of comfort.
°Now, I don't remember if this is specifically stated in the books, but there have been several posts about his favourite colour being red because it's the colour of Castelline. While Lin's favourite colour is gold.
Gold doesn't need much explanation. It's Conor's family colour and he's seen wearing it throughout most of the book.
While in Conor's case, I doubt that Red would be his favourite colour since he's so against it in the beginning of the book and only ever wears gold. He starts incorporating red after he meets Lin, after he already associates it with her.
Maybe this was obvious already to everyone, but I found It a particularly heartbreaking detail, how Conor is forced to choose between his happiness with Lin and the good of the Kingdom, and the way it's represented through colour. His favourite colour is red because of Lin's hair, but he chooses Castelline's red instead, because he has to look out after his kingdom.
