A friend just sent me a link on synesthesia. I definitely fall into the numbers-having-colors category. For example, two has been yellow, three has been green, and four has been red ever since I learned to count. 4,196 is black, red, and grey (and all of those colors get more intense if you remove the comma; they tend to dilute numbers). 9 is also a shade of red, and 1 is dark grey (varying in shade depending on context) while 6 is black. However, 239857 when taken together is a lightish blue, despite its constituent digits — the red of the 9 gets drowned out completely by everyone else. 8’s are yellow, 5’s are brown, 7’s are grey with a hint of pale blue. The constant e (~2.718), so commonly used interest computations in accounting, is appropriately a disturbing, disorienting combination of its constituent yellows and greys. One of the reasons π is my favorite number is because it’s so Christmasy (the 1 after the decimal is nearly invisible to me).
Letters also have color for me, as do words (e.g. “letters” as a word is a light, tannish fleshtone despite the strong red and black of the r and t’s, respectively). Vowels are highly saturated, bright colors, while consonants are duller but have subtler variations in value. And so on.
Music doesn’t have color or imagery for me, but it has movement — more precisely, I associate it with tactile sensations. I often find myself doing things with my hands when I listen to music alone. Not just drumming my fingers or “playing” along, but just doing weird things that it looks like an autistic person might do. And, like the unconventional behaviors of autism, I find such movements extremely satisfying/comforting.
Words, both written and spoken, also elicit a tactile response in me. Clavier, incommunicably, Gothic, and Esgalduin are all very tactilely pleasing words to me. It’s hard to generalize what will make a word feel good to me, but it almost always has to have a non-aspirated glottal consonant in it, and I happen not to aspirate any of the consonants in those words.
Okay, I think I’ve beaten this topic to absurdity now (despite the fact that I could write much more). Maybe I should actually read more than the first paragraph of that web page, just in case it says something like “people who have this thing are really, really screwed.”