Born in Byala, Rousse Province, Kolev underwent trials in the Litex Lovech youth academy after just two training sessions. His first coach was Yordan Yordanov. He progressed through all age groups at the academy, coached by specialists including Stefan Yarmov, Plamen Linkov, and Nikolay Dimitrov-Dzhaych. As a youth player, he won the Juliy Manzarov Cup in 2005. The same year, he also secured a bronze medal in the Bulgarian Football Union Cup (again with the 1987 cohort at Litex). In 2006, he was named "Best Youth Player" at the academy and was earmarked as the heir to the legendary Nebojša Jelenković.
Kolev's performances caught the attention of then-head coach Lyubko Petrovich. The promising talent began training with the first team, participating in 7-8 friendly matches, but never made an official debut for the senior squad. In July 2007, he was sent on a trial at PFC Lokomotiv Mezdra and later signed a professional contract. Despite a strong preseason, he did not get a chance to play, and during the winter break, he was loaned to Benkovski Byala. After the season ended, Mezdra did not offer him a long-term contract, and he signed with Kom-Minyor. His impressive displays attracted the attention of top Bulgarian clubs. In 2009, he was a member of the Bulgaria national under-21 football team.[2][3]
In early February 2011, he signed a one-and-a-half-year contract with elite club OFC Sliven 2000, with his former club Berkovitsa entitled to receive 30% of his future transfer fee. He had a stint at Moldovan club Kostuleni, where his coach was Velizar Popov. Since 2012, he has been competing for Montenegrin club Cetinje Niksic. On October 22, 2012, he was named Player of the Round in the Montenegrin league. In the winter break of the 2011–12 season, he moved first time abroad, to play with Moldovan National Division side FC Costuleni. Then in the summer of 2012 he moved to Montenegro where he signed for FK Čelik Nikšić.[2]
Darts career
In 2020, during the coronavirus pandemic, Kolev ventured into the sport of darts. Over the following years, he honed his skills in Iceland, where he participated in his first international tournament. In his debut year at the international level, he advanced to the final of the 2024 Faroe Islands Darts Open, where he faced Edwin Torbjörnsson and lost with a score of 3–5 legs in that final match. This marked a significant milestone in Kolev's darting career, showcasing his rapid progress.