This reminds me of musicians, particularly those with perfect pitch, who talk of 'colours' of keys. While it's not a direct analogy, perhaps one way to think o

This reminds me of musicians, particularly those with perfect pitch, who talk of 'colours' of keys. While it's not a direct analogy, perhaps one way to think of colour, if you've never seen it before, is to think of different wavelengths of sounds being a bit like different wavelengths of light.