I have no idea if there is a 'tradition' per se. Personally, I have tried all sorts of different color bows, and red is the only one that really makes the blue and tan in the coat 'pop'. Example: Green makes the tan look washed-out and grey. So, red just works the best for me because it compliments the coloring the best. Other colors just don't show the real full color spectrum in the coat. I hope that makes sense.
