I work for a psychometrics company, and having been tested to within an inch of my life, I know I'm primarily a visual person (as opposed to auditory, kinasthetic or data-rational). I definitely see chords as colours.

E - green
Em - dark green
A - red
Am - dark red
C - dark blue
G - dark brown
D - beige
F - sort of grey-black
Strangely no yellows though...

I learned by ear rather than having lessons which is something I am now going back to do. Last week it was chord ornaments, and we wrote out some chord diagrams to show sus4s, 6s, maj7s etc. but I found it much easier to remeber if I did all the Es in green, all the As in red...etc.

Did anyone decide on the colours or were they just there in your mind?