There is a sensory perceptual disorder called synaesthesia, where the sense can be mixed up, like you "feel" a color, or "taste" a color. Some autistics have written about this and a book I have by Olga Bogdashina, "Sensory Perceptual Issues in Autism and Asperger Syndrome" talks about all the differences in the senses. She identifies it as "the stimulation of one sensory modality triggers a perception in one or more different senses." Examples are when sound or smell or touch or taste triggers the perception of a color, when sound, sight, taste is experienced as a shape or tactile sensation. There are also colored-numbers, whether heard or read, which is the basis for The Brain Man, Daniel Tammet, the English fellow who wrote his story in "Born on a Blue Day". There are color-letters, color-graphemes where letters or words are experienced as colors.
My son has started to tell us that certain touches have color. Mommies kisses are "red" and Daddies kisses are "blue". He like blue kisses only. Nick's kisses are "blue". So I am wondering about this in my son.
Dr. Simon Baron-Cohen has estimated that 1 in 2,000 may have synaesthesia, and women predominate at a ratio from 3:1 to 8:1. It is more frequent in Left-handed people, and is believed to be genetic. 15% of people with synaesthesia have a history of one of their first-degree relatives having dyslexia, autism, or ADD. The actual incidence of synaesthesia in the ASD population is unknown.