A number of options are available, but I've had good luck with 1st an oil base polyurethane 'stain' in the color you like; then an oil base polyurethane in whichever finish you want---satin, semi-gloss, gloss, matte, etc.
A traditional oil finish like Watco or Tung Oil can also do a nice job.
Color will depend on the wood you are staining/oiling. The only place you could 'test for color' is on the inside of the grip.