The Color of Numbers and Letters

4.0 based on 89 ratings

Updated on Mar 14, 2013

Grade Level: 6th to 8th; Type: Social Science


This project explores whether and what associations exist between numbers and letters and colors.

Research Question:

  • Do certain numbers or letters make a high percentage of people think of the same color?

Synesthesia is a condition in which a sense-impression is involuntarily produced by the stimulation of another sense. In the most common form of the condition, grapheme-color synesthesia, letters and numerals are perceived as certain colors. For example A is seen as red and the number 1 as blue. People, of course, may make cultural or personal grapheme-color associations without having actual neurologically-based synesthesia. In this project you will test people for synesthesia while looking for common culturally-based grapheme-color associations.


  • Computer with internet access
  • Color printer
  • Paper
  • Test subjects
  • Paper and pencil for recording and analyzing data

Experimental Procedure

  1. Print out IN COLOR Test Square #1 and Test Square #2 from this web page: “Test Your Synesthesia,” Mind Hacks
  2. Print out the numbers one through nine and the letters of the alphabet, each on its own sheet of paper, in a large, simple font, in black and white.
  3. Ask each test subject to look at the symbols in Test Square #1 and pick out the red ones. The subject should be able to spot the red ones instantly.
  4. Next show the subject the collection of symbols in Test Square #2 and ask him to spot the ones that are different. For almost all people (possibly all of your test subjects) this will take more time and effort. The symbols, rather than jumping-out-at-you the way the red ones did in the previous square, will have to be reviewed one-by-one. Except of course in the rare event that the subject is a true grapheme-color synesthete in which case the 2s and the 5s will appear to be different colors.
  5. Now with subjects whom you have determined are not synesthetic, show them one-by-one the numerals one through nine and each letter of the alphabet and ask them what color they think of when they see that number/letter. Record responses.
  6. Analyze subjects’ responses. Did certain numbers or letters make a high percentage of people think of the same color? For example, the number 1 might cause a lot of people to think of blue.
  7. Propose possible cultural explanations for any patterns you discover. For example, perhaps the number 1 makes people think of blue because blue ribbons indicate 1st place.

Terms/Concepts: synesthesia, synesthete, synesthetic, grapheme-color synesthesia


How likely are you to recommend to your friends and colleagues?

Not at all likely
Extremely likely