Cool, good luck. I would love to show Otis too, but don't know how well it would go because he is the "wrong" colored brindle..hate to set myself and Otis up for disappointment. I wish you great luck and I know peeps will guide you in the right direction with this..keep us updated, please.
I know lots of Dark Brindles… they are pretty common really, just like "light" colored Brindles... so should not really be a consideration in the ring... there are still a lot of judges that we call "red or dead" judges. Meaning they only will use Red/White dogs, but we have so many really nice dogs showing now of all the colors, it is not as bad as it used to be. When I started showing, if you had a Black/White or Tri... you were truly a minority...ggg.. not that way much anymore....
That said, when you show... best you are ready for "disappointment"... because you lose more times then you win...gggg... You need to be able to go into the ring with "I have the best dog here" attitude but be ready to accept not winning...and even getting beat by a dog that you might feel is not as good as yours... In other words... you need to have a "thick" skin for the show ring... along with being honest about your own dog and knowing their faults.
When asking for opinions, understand that most people will not be brutally honest.. they will point out the good things and gloss over the bad... so sometimes when asking for opinions you may not really be hearing the down and dirty truth about your own dog.