Both are tragic romances between two characters who trapped by circumstances and are forced to act against their better natures. While Bloody Romance has the kind FL trapped with the powerful ML who decides to help her, The Blue Whisper has the kind ML as the one who gets trapped at the start with the powerful FL helping him. The characters are forced into conflicts that they would rather avoid and work against those in power who are mostly villainous. There are betrayals and misunderstandings, but the leads end up growing as people. Both explore the complexities of morality.
female characters are strong and badass. Both are about an organisation that sends people to uncover mysteries/ do jobs set in historical times. Eventual romance between certain teammates. Young blood is about a government spy orignisation however, wheras bloody romance is about assasination jobs. young blood has a team of main characters whereas bloodyromance has only the two.
Both are fantasy/historical/wuxia dramas with a more unique plot, aesthetic, and characters, and a similar feel. Both deal with complex court politics, birth secrets involving the rightful heir to the throne, assassins, and feature a love triangle. Both FLs are compassionate and become stronger over the drama despite suffering a lot. The MLs are tortured slaves/servant bodyguards whose only purpose is to shield and die for their female masters, and both end up belonging to the FL early in the dramas. Both love stories are angsty and heart-breaking, and the dramas have unique endings - Bloody Romance is bittersweet, open, but hopeful, Colourful Bone has two endings, one sad/bittersweet and the other happy.