Joláthy studied at the Military Prodoschool in Marosvásárhely between 1942 and 1944, then spent the next two years in American captivity in Ludwigshafen. In the post-war years he worked in the Standard factory, first as a title painter, then as a technical draftsman, and later as an editing technician at the Ventilation Works in Albertfalva. At the factory artist circle he was taught by Emil Róbert Novotny. Joláthy's attraction to industrialist art, which spans his entire oeuvre, can be traced back to these years. However, he began his artistic career in the early 1950s as a figural painter, a pupil of Ödön Márffy at the Buda Fine Art Circle. Later, between 1952 and 1955, he worked as a teaching assistant to Márffy. Joláthy was thus able to inherit the spirituality of the Eight from Márffy.
In 1956, he moved to France, where he worked as a pictorial painter using intense colors. From 1958 to 1960, he was a student at the Grand Chaumiére Private Academy in Paris, where Amrita Sher-Gil, Alexander Calder and Louise Bourgeois studied as well. He started creating on his own in the sixties. In 1962, he co-founded the Art 62 group in Évry, near Paris. A defining experience for him in France was the Egyptian collection of the Louvre, the transcripts of which he summarized in paintings using decorative colors and thickly applied layers of paint. From the sixties, Joláthy went beyond his initial period - a representation based on Márffy's figural influence and impressionism - and turned to the style of geometry and constructivism. He became a permanent exhibitor at the Galerie de la Chouette from 1967 and in 1969 took part in the Espace et Lumiére exhibition at the Grand Palais.
Joláthy moved back to Hungary in 1974. The geometric shapes, machines and structures dimmed in its world of colors came to the exclusive attention of its attention. In 1976, he became a participant in the founding of the Józsefváros Exhibition Hall and ran the screen workshop of the Tokaj Artists' Colony from 1980 until his death. From 1981 he was a professional consultant at the National Center for Public Culture.