The issue of sound and color is one that comes up a lot in the Zen tradition, because it is central to awakening. In the Diamond Sutra, Chapter 26, we find this verse:
Seeking me by using form/color
or seeking me by using the sound of my voice
A person walks a mistaken path
And cannot perceive the Tathagata
Yet, the Third Ancestor said, “The six senses are not evil. Even more, they are the same as true awakening.”
If we chase after sound and color, or if we hide from sound and color, we miss the tathagata. Yet if the six senses are the same as true awakening, how can we walk a true path, hearing and seeing the tathagata?
The case below, if taken up wholeheartedly, has the power to open the door of awakening. Old Yúnmén even has compassion showing up as a steamed dumpling!
The issue of sound and color, by the way, is raised in several chapters of Going Through the Mystery's One Hundred Questions, including "Question 61: Are there no Bodhisattvas of Compassion who enter the gate of the inner pattern?"; "Question 62: What is thoroughly penetrating?"; and “Question 92: Why follow sounds and chase colors?"
The following is from Record of Going Easy, (J. Shoyoroku), collected and with the verses by Hóngzhì (1091-1157). The introduction and capping phrases (J. jakugo) are by Wànsōng (1166–1246). These are indented and italicized.
Case 82 Yúnmén's Sound and Color
Presenting to the assembly, saying:
Unceasing sound and color fall everywhere. Seeking sound, seeing color, not meeting the Tathagata. Is there anyone who can engage the path and return to their family home?
Yúnmén presented to the assembly, saying, “Hearing sound, realizing the way.
Two balls of earwax.
Seeing color, clarifying the mind.
A pair of leaves screening the eye.
Guanyin Bodhisattva uses money to buy a pastry. Letting go [of their] hold - actually it’s the best steamed dumpling.”
Every way the wind blows, leaves harmony within.
Leave home on a galloping horse, grab the broom, sweep against the grain
Outside the threshold, it’s the general’s command
The smoke and dust of each and every land is self purifying
The wind blows the grass down
The twelve sense bases extinguish enclosed shadows and echoes
The combination makes for one family
All three thousand worlds emit radiant light (J., kōmyō)
Still there is no second form