The Boxer does not carry the gene for a black coat color. I have dark reverse brindle Boxers that appear to be black, they have very dark brindle coats that have so many dark brindle lines that it appears to make the coat completely black. It is not really black, it just has excessive dark stripes.

Capone, sealed brindle, in the sunlight, notice the brindling.

Picture of Capone by Manuela Dos Passos-Ionta

TIHA - NOTICE THE BRINDLING.

My Boxers are not rare black Boxers, they are dark brindle in color. My litters have tiger brindle's, reverse brindle's, dark reverse brindle's, and brindles. Sealed brindle is not a color that is any different to any other shade of brindle. It is a term used in North America simply to describe a dog that has such a heavy concentration of brindle stripes so as to have the appearance of being a dark dog. The opposite is "light" brindle - describing a dog that has very few brindle stripes. And in between all that, there is "golden" brindle, "fawn" brindle, "brown" brindle, "red" brindle, "mahogany" brindle, etc. These simply describe the shade of fawn ground color, exactly the same as for differing shades of solid fawn boxers.

DARK BRINDLE PUPS "VIOLET AND LUCKY" MOXIE/CAPONE LITTER