How are graphemes related to synesthesia?

Grapheme-color synesthesia is a consistent brain-related phenomenon. A syneshete automatically associates distinct, consistent colors with certain letters, numbers, and/or words. A word that is printed in black on a page or wall in front of you will carry its own specific color when you see it.

Grapheme–color synesthesia or colored grapheme synesthesia is a form of synesthesia in which an individual's perception of numerals and letters is associated with the experience of colors. Like all forms of synesthesia, grapheme–color synesthesia is involuntary, consistent and memorable.

Explanation:

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