I have it, and I just recently found out the name for it. I'd always try to explain to people how certain numbers for me were always yellow, that the month of January was way far to the left, and there was once a girl who I swore "talked like butter," but nobody understood what the hell I meant

Here's a website about it, and the wikipedia page:
http://www.psychol.ucl.ac.uk/jamie.ward ... thesia.htm
http://en.wikipedia.org/wiki/Synesthesia