Call the white one Feta, and the brown one Billy.
we once had two twin billys and named them after our favorite country singers: Luke and Bryan, Blake and Shelton, Brooks and Dunn, Dierks and Bently. Just for some examples!
Buck, Duke, Ram, Billy, Bob, Willy, Beau, Gumbo, Bash, and Bambam.
Please call them Brian and Matt. I would love you forever. (long story) If not, how about; Caliver, Buck, Remington, Wesson, Dewey, Glenn, Daryl, Buster, Forrest Good luck and hope this helps! :)