It was an 18+ smut manga with a Middle Eastern/South Asia type setting, like Aladdin. MC’s sister is threatened to be sold into slavery but MC takes her place instead. He is brought to a kingdom with 5 different princes named after colors. He is enslaved by the black (or red?) prince and treated badly. However, he meets the blue or yellow prince who is nice to him and they fall in love. The main story then follows MC trying to escape his abusive master and join the nice prince, but the black prince making his life miserable doesn’t want to let him go. From what I remember the English translation was incomplete when I last read it.
Does this ring a bell for anyone?? 🙏🏼