Cat whiskers are so neat. Gandalf's are all white, lone and straight. Samwise on the other hand, his are dark nearly the color of his fur, short and curved.
Whiskers can be all sorts of colors, they usually match the color of the cat. Ali's whiskers are black at the roots and for about 1/3 of the whisker and the other 2/3 is white.
Marcellus, who is all black, had all black whiskers when he was little with the exception of one white whisker on each side. We thought that so cute. Well, he eventually lost those white whiskers, not sure if they fall out and get replaced or just grow, I assume they get replaced. Anyway, no white whiskers now, all are black.
One of my kittens has whiskers that are black the half towards his face, and white at the other end. The vet thought that was odd. Both have black and white whiskers.
Hans is a piebald and has white wiskers. Merlin and L.S. both have silver-grey whiskers that match their fur.
HoHo (one of the shelter cats) has all black whiskers except for one white one on the right side. It's the only way I can tell him apart from a distance.
Willow's whiskers are multicolored, just like her fur. Several are two or three colors on the same whisker! Spot's are all white. My boyfriend's folks have a solid gray cat and a solid black cat, and both have whiskers that match their fur. My mom's cat used to have mostly black whiskers, but as she has gotten older, a lot of them have turned white.