Kol from The Vampire Diaries
Kol is a pretty straight-forward old Viking name meaning "coal," in Old Norse, but it can also mean "dark," and "black." Cole/Kole, Colby/Kolby and Colton/Kolton are the most common variations seen today, and Kol/Col is a pretty common name prefix and suffix. It is more commonly seen as Cole or Kole due to it's transfer into Old English usage. Kolt/Colt and Kolton/Colton both meaning "coal town," although Colt can also refer to a young male horse. Now, the most common namesake right now is the fictional character Kol from The Vampire Diaries, part of an ancient Viking line turned vampire.
There is a female variant, Kolfinna, meaning "dark (from the coal element) and fair," which is well used in Iceland, and there were no recorded births for it (ever) in the U.S. There's also the male Scandinavian variant Kolbjorn, which has not seen use in the U.S.
In 2011 there were 9 baby boys named Khole, 9 Kolden, 13 Kol, 699 Kolton, ranking at #403, 349 Kole, ranking at #671, 321 Kolby, ranking at #706, 291 Kolten, ranking at #766, 111 Kolt, and 34 Kolson, as well as a handful of various other non-traditional spellings. Cole currently ranks at #94, Colt ranks at #326, Colby ranks at #314, and Colton ranks at #74. Fast forward to 2016 and there were 612 named Kolton, 290 Kole, 271 Kolten, 216 Kolby, 122 Kolt, 58 Koltyn, 36 Kolson, 22 Kolston, 17 Kolsen, 16 Kol, 13 Koleman, 9 Koltan, 8 Kolsten