Cool Blue is the Dj name of Bulgarian girl called Denitsa. She enters the world of Dj's from 1999 as a member of Tranzmission - organization which contributed to the development of the underground scene in Bulgaria at that time.

Cool Blue was playing in most electronic clubs in the country. Participated in International multimedia techno trance festival-Plovdiv (2001), playing alongside Andrew Rishley and Ryan Rivera (AMC