When he was still a child he emigrated with his family to Buenos Aires, where he started his studies on painting in 1917. Back to Galicia again he made his first exhibition in 1928 at the galleries of Faro de Vigo. From this year until 1936 he would make exhibitions in different cities of Galicia apart from Lisbon, Bilbao and Barcelona. In 1937 he married Emilia González and had three children.
The theme in his painting was mainly based on the Galician country and people. He painted fairs, festivities, peasants working or keeping the cattle and so on. Colmeiro made the following individual exhibitions:-Maragal Gallery (Barcelona, 1931).-Círculo de Bellas Artes (Madrid, 1932).-Palacio de España (Lisboa, 1932).-Amigos del Arte (Buenos Aires, 1937).-Instituto Francés de Estudios (Buenos Aires, 1943).-Müller Gallery ( Buenos Aires, 1947).-Zack Gallery (París, 1950).-Biosca Gallery (Madrid, 1958).-St Catalina Gallery and Culture Centre in Madrid (Madrid, 1961).-Broadway Gallery (Londres, 1964).-Galería du Passeur (París, 1965).-Biosca Gallery (Madrid, 1965).-Biosca Gallery (Madrid, 1972).-Biosca Gallery (Madrid, 1975).Many os his paintings are placed in several Spanish and foreign museums.