Well, very few synesthetes see the exact same color for a given letter. And since it also gives letters texture, lighting, and maybe even gender and personality, it's almost impossible to find two people with the same image of a letter--and they will be DAMN SPECIFIC about finding the EXACT SHADE OF GREEN, too.

BUT--certain letters do seem to evoke general trends. I remember the o one because it was so different from mine, but I don't remember any of the others. I do remember comparing my alphabet to a few other people's samples and finding that we were all way off from each other.

They say that everyone has a little bit of it, as reflected by terms like "loud colors" or the bouba-kiki effect. So you may have some already!