Whoa! I think I may be having a weaker version of the same type of synesthesia that you have described. I tend to "imagine" colours when I think of certain letters, numbers, days or months. I don't feel this way for each one of them though.. for eg. 2 = red, 4 = green, 5 = pink, 6 = blue, 7 = purple whereas nothing for 0, 1, 3, 8 and 9 (may be black?). Similarly, E = yellow, F = pink, saturday = green, march = yellow etc. Also, I don't "see" colours while reading text, just when I happen to think more about a letter, number or word.
All this while I was thinking this is common and normal in all people like photographic memory or something. Learnt something new today :-)
All this while I was thinking this is common and normal in all people like photographic memory or something. Learnt something new today :-)