Juan is an observant, mixed-race youth born into slavery in 17th-century Spain. After losing his mother at a young age, he learns to survive the precarious life of enslavement, eventually joining the household of prominent painter Diego Velázquez in Madrid. He possesses a deep sensitivity to human emotions and animal suffering. Behind his quiet obedience, he harbors a growing, secret fascination with the art of painting.

Diego is an esteemed Spanish Golden Age painter who establishes a studio in Madrid to serve King Philip IV. He is intensely focused on his craft, prioritizing the objective capture of truth over flattery or ornamentation. Characterized by his simple black attire, he maintains an emotionally reserved but thoughtful household, treating those around him with a cool, distant gentility.

King Philip IV of Spain is a powerful yet deeply shy monarch who commissions Diego to curate his art collection. Distrustful of typical court sycophants, he seeks out the quiet sanctuary of Diego's studio to escape his royal pressures. He often shows more affection to his hunting dogs than to his human courtiers, hiding his physical insecurities behind rigid royal protocols.

Miri is an enslaved young girl who travels with the Flemish painter's entourage. She is highly expressive and musically gifted, accompanying her sorrowful singing with a lyre. Prone to severe epileptic seizures, she lives in constant fear that her enslaver will discard her when she becomes too burdensome.

Lolis is a strong-willed, hot-tempered enslaved woman purchased by the Velázquez family to assist in the kitchen and tend to Juana. She carries a cynical view of white society and fiercely resents her enslavement, refusing to compromise her desire for ultimate freedom. Despite her defensive exterior, she proves to be a capable caretaker.

Francisca is the eldest daughter of Diego and Juana Velázquez. Endowed with a gentle nature and an affinity for small animals, she grows from a lively child into a beautiful young woman. Her affectionate disposition allows her to easily win the devotion of those around her.

Murillo is a deeply religious and kindhearted aspiring artist who travels from Seville to learn from Diego Velázquez. Characterized by his cheerful disposition and devotion to his Christian faith, he firmly believes that the divine resides in all people. He extends genuine respect to Juan, addressing him formally rather than with a diminutive nickname.

Juana is Diego Velázquez's wife and the mistress of their household in Madrid. She manages the domestic sphere, including overseeing the apprentices and maintaining the family's wardrobe. She occasionally desires the glamour of court life but remains a devoted partner who supports her husband's singular focus on his work.

Zulema is an enslaved Black woman living in Seville. She provides a sense of safety and unconditional love for her young son, Juan. She leaves him with a pair of gold earrings before passing away from disease when he is five years old.

Doña Emilia is a wealthy woman in Seville and Juan's first enslaver. She is temperamental but occasionally kind, choosing to teach Juan to read and write primarily so he can manage her correspondence. Her household is eventually devastated by a sudden plague outbreak.

Brother Isidro is a humble Franciscan friar who wears a simple, worn robe and dedicates his life to the impoverished. Rejecting the social hierarchies of 17th-century Spain, he treats Juan as a human being made in God's image rather than an enslaved piece of property.

Don Carmelo is a brutish Romani mule driver who illicitly uses an aristocratic honorific to project power. He frequently threatens and physically abuses Juan during their journey, attempting to force the boy to beg and steal to survive on the road.

Don Dimas is a local baker who offers Juan temporary employment on his journey to Madrid. He provides Juan with food, shelter, and a patched coat in exchange for forty days of labor at his bakery.

Ignacia is the younger of Diego and Juana's two daughters. She plays alongside her sister Francisca and enjoys the household pets, remaining a quiet presence in the family's domestic life before illness strikes the city.

Juan Bautista is a young, dedicated artist who arrives to apprentice under Diego Velázquez. He is immediately captivated by his master's eldest daughter, Francisca, and must rely on secret notes passed through servants to court her safely.

Francisco Lezcano is one of the little people retained by the King for court entertainment. He suffers from chronic muscle pain and carries a deep bitterness about his social position, but he finds comfort in Juan's sympathetic massages and understanding nature.

Cristobal is an apprentice painter who frequently attempts to implicate Juan in his mischievous acts. Though his moral character is questionable and he tends to superficially beautify his still-life paintings, Diego retains him purely due to his exceptional raw talent.

Rubens is a highly accomplished and celebrated Flemish painter. He tours Madrid with Diego Velázquez as his guide, seeking artistic inspiration and demonstrating his renowned techniques to the relatively stiff Spanish court.

Gil Medina is an esteemed local image maker who crafts highly detailed wooden crucifixes. His dedication to capturing authentic suffering leads him to exploit condemned criminals, using them as live models in cruel mock-crucifixions to achieve greater realism.

Pope Innocent X is the head of the Catholic Church who asks Diego to paint his portrait while the artist is stationed in Rome. He possesses a powerful, severe countenance that requires Diego's utmost skill to capture without resorting to flat flattery.