I loved that "cafe babe" was first used in reference to cute baristas at Peet's Coffee & Tea
The most straightforward explanation of the name is hexspeak. The hexadecimal numeral system uses a base of 16, where the numbers 0 - 9 are used for the first 10 digits, and the letters A - F are used for the last 6. Using these digits, it is possible to spell words.