I wish it could be that simple. It would help my harmonies probably. But timbre and even volume have an effect on color and texture to me. In controlled conditions, like my studio, quiet, the guitar and strings i'm used to, I can tune to color, but the time of day, and ambient lighting, can make me a little sharp or flat.
I have Synesthesia.. specifically and in this order:
sound>sight(shape, texture, color, movement) - basically all sound stimuli.
sight>sound - many subdued colors, and anything without a strong repeating pattern are so quiet I basically don't notice them most of the time.
and
smell>sight - even less mixed up than sight>sound. Very light tinge of color over my eyes except for really loud smells like a skunk. So quiet I basically don't see but the rarest smells unless it is quiet and I close my eyes.
http://www.disabled-world.com/health...ynesthesia.php