Rockabilly stems from the birth of rock n' roll as it began to emerge from bluegrass and country music. Nowadays the term covers a whole subculture that takes its cues from the fashion and style and trends of the rebellious, edgy rockabilly era of the 40s and 50s. (That's right: the 50s weren't all June-Cleaver-pearls.) What does this mean for you? It means amazing vintage, pin-up style hair trends that you can make your own.
If you want to go all out rockabilly, overhaul your look with elements like short cropped bangs ala Bettie Page and either going root-to-tip black or adding bright colors to your hair like cherry red, either all over or in strategic places.