Odd colored cochin.

[onthespot]

I don't see any white polka dots on the dark feathers. I agree... not mottled. Not splash either, because none of the white feathers have splash ribs.

 

[Sonoran Silkies]

Splash ribs?

 

[onthespot]

the hard part down the middle of the feather. I guess I meant shaft. My splashes all have scattered dark shafts on their feathers.

 

[Dustin Biery]

I really have no explaination of the pattern either, but just wanted to throw in there that it isn't mottled. I think you may just have a white bird with black feathers...

 

[insiderart]

So it looks like it's a paint then? Cool!

 

[Sonoran Silkies]

I wouldn't jump onto the idea of paint unless the OP comes back and says that all feathers are one colour or the other, no feather has both black and white. Then I would say "maybe," and ask those who are familiar with paints their opinion.