RGBYW sounds should not be regenerated on the fly using the sin equations. They should be buffered separately and then added together based on the intensity of the color.
The current sounds were determined pretty arbitrarily by whatever I thought was good. Investigate the sound timbre and pitches used for RGBYW and determine optimal sounds, keeping in mind the following:
Discernibility. The sounds should be distinguishable from each other
Pleasantness. The sounds should be pleasing, especially when hearing something traditionally considered beautiful (i.e, a sunset should sound nice).
Environment. The sounds should be distinguishable from most indoor and outdoor environments, but should not obscure the environmental sounds.