Love this topic, funny I was just thinking about it the other day. I probably posted this in a prev. thread, but my sister does have number-color syna. I am so jealous, it sounds fabulous! Are there drawbacks?
I haven't heard of any.

She also has genders for the various numbers, my ds has mentioned this as well, although not colors. I did read that people who have been tested will come back year after year, many years between tests and note the exact same colors/attributes for numbers.

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