(I hope I’m not double posting. The board went weird on me during my first try.)
This is TwoTone the cat. He’s a very sweet kitty with a two colored coat like I’ve never seen or heard of before. He has a solid black top coat, and a shorter, softer undercoat that is snowy white.
Is he a rare breed, a mutant, or what? Anybody?
My Gwen is colored like that - she’s a dilute tortiseshell, but if you part her hair her undercoat is white. And when I brush her, all the hair in the brush looks white.
Its called an agouti pattern, the shaft of the hair is a different color closer to the skin. Its a common genetic coat pattern.
He is beautiful!
I thought it was called agouti too, until I looked it up at Cat Fanciers:
Apparently there’s a difference between individual agouti hairs and an overall agouti pattern.
More on cat color genetics at Wiki.
Well, my knowledge is rabbits, and with them it would probably be considered agouti. Meh, cats, rabbits, same difference, right?
Surely those hairs can’t change color halfway through growth - if the hair shaft is two-tone, why don’t the white bits end up on the outside of the fur?
Sure, I always remember that the Cat Fanciers are the same folks that want me to call my Big Orange Tomcat Red. 
Smokes are common in persians I raised them for a while. I had blue smokes, white undercoat, gray outer coat, black smokes, like the one pictured, and one red smoke. Marmalade outer coat, with white under. I almost kept that one, but she wasn’t very bright.
They do, though. While not as dramatic an effect as TwoTone (pretty cat!), my cat has a semi-“ticked” coat. A hair from her fur looks like this:
[====buff======][black][==brown==][black]
Here’s a good link: http://www.gorki.net/habits/appearance.html
Some other interesting black and white cats. None quite the same as your cat, though.
The cat in the picture is not like that. Most cats, have two layers of hair. The exception to that are the Rex breeds that are missing the outer layer of hair.
Most of the time, normally haired cats outer and inner layers are the same color, the exception here are the “smoke” colors, who have a white inner coat and colored outer coat.
I’m not questioning the effect you’ve pointed out, but it’s isn’t the same thing.
