Version 2
New brown brindle:
Brown brindle (transparency: 25, base 99)

 

 

Black brindle (transparency: 25, base 35)

Brown brindle (transparency: 25, base 59)

Both use this furfile:

Because of the nature of the furfile, dogs can gain new mutated brindles, not just the two above. For instance a wheaten and a brindle could produce a wheaten brindle.

Examples of RL dogs:

Black brindle: http://clubs.akc.org/stca/images/dkbr1.jpg

Brown brindle: http://clubs.akc.org/stca/images/rdbr1.jpg