Do I have synesthesia? Help.

Since as far back as I can remember, I've always associated each vowel with a color. "A" with magenta, pink and red, "e" with green, "i" with yellow, "o" with dark brown and black, and "u" with blue.

I don't physically see those letters painted with that colors when they aren't, I just make a very strong connection in my mind between them.

Is this some kind of mild synesthesia?