He was born into an established colonial family. His artistic talent was noticed at an early age by one of his instructors at school in Santiago.His first studies were probably conducted in his native city under the guidance of Federico Martinez, as certain characteristics of his painting relate him to this artist. While at school, he was motivated to become an independence fighter following the death by firing squad of one of his cousins, at the age of only seventeen. At the beginning of the Ten Years' War, his parents, aware of his activities and concerned for his safety, hastily put him on board a ship headed for the United States.
His passion for the Fine Arts, directs him toward this path in New York, where he works as a colorist in a photography studio. After some years, he opens his own studio and then promptly achieves fame as a noted portraitist.
In 1883, Collazo returns to Cuba after this prolonged absence and settles in Havana, where he remains for some years until moving permanently to France. When Collazo returns to Havana, he has become a painter with a thorough mastery of technique. Julián del Casal in his Crónicas describes his luxurious studio, which was frequented by arts aficionados and a select clientele in search of a good portrait.
Besides being a memorable portrait painter, the artist also realized landscapes and composition pieces. With technical dexterity and a rich chromatic gamut, he is capable of achieving splendid grays charged with pigments. His work is dominated by his characteristically elegant drawing. His models are always refined, to the point of rejecting professionals and utilizing friends and family members in his compositions. Two of his most distinctive works, La siesta, 1886 (The Nap) and Dama sentada a orillas del mar, 1891 (Lady Seated by the Seashore) are displayed at the National Museum of Fine Arts. Collazo died in Paris in 1896.