What does Cole mean?
Partly from Old English 'col' meaning 'coal', used as a nickname for someone of dark or swarthy complexion or black hair. Note: Cole can also be a short form of Nicholas, which is unrelated to 'dark', so the dark sense is one origin among two.
What does Randall mean?
Medieval English form of the Old English name Randwulf, from 'rand' ('shield, rim') and 'wulf' ('wolf'), meaning 'shield wolf'. Shares its root and sense with Randolph.