I realised some years ago that I associate colours with particular letters. I don’t know how common this is amongst people with Aspergers or whether it is even related. Some colour-letter associations are stronger for me than others:
- A is always bright red. The following letters then graduate through orange to yellow.
- M and letters around it are blue.
- O, P and Q are purple.
- S and T are green. R doesn’t have a strong association.
- U is brown.
- V through Z start mid-grey and get darker.
If I see one of those letters in a different colour it feels wrong and makes me uncomfortable. Strangely, I don’t have any similar associations for numbers or words. I wonder whether other Aspies experience anything similar?
My Autistic Dance 
I also have aspergers and see letters in colour. My A's are red as are my R's. My E's are orange, W is grey. (I won't bore you by going through them all.
LikeLike