Look for the art of pattern. Taisho-Sanshoku expresses the art of pattern in red, black, and white. In the case of Aka-Sanke (red-sanke), even if the white skin does not have Sumi, the presence of a graceful and powerful Kata-Sumi (shoulder-sumi), is highly praised as it will express an artistic pattern. As a matter of fact, Aka-Sanke with Katasumi received the top prize at the Japanese National championship a few years ago.
"Art of Pattern" means that the presence of sumi on the shoulder stamps stability for the pattern into the whole pattern layout, and as a result, it creates a balance in its entirety. In terms of Sanshoku (tri-color), the impact is strongest when the Hi is on the head and Sumi on the shoulder. In this layout, the Sumi appears as if it is pressing down and holding the entire layout of the pattern together.
Pattern is an expression of beauty, and beauty is best expressed when the pattern is simple. One will never get bored with the beauty of a simple and yet, playful and well-balanced pattern. For the sophisticated hobbyist or the judge, the question is whether to have many complex patterns, or simply to have a limited amount of beautiful patterns to achieve beauty.
Clearly, a significant Sumi on the shoulder will look more graceful and beautiful. Instead of wearing beautiful jewelry on all five fingers, wearing just one major piece of jewelry on one finger will be a much more powerful aesthetic statement. In traditional Japanese flower arrangement, the same concept is applied: in order to maximize the beauty of a flower, the surrounding flowers are eliminated.
I thought this might bring a little understanding into how the Japanese view pattern.