about 2 years ago, i got the gogh clog in amethyst size 9 for a very good sale price here on amazon. i liked them enough to want to get a second/replacement pair. first i ordered the chocolate brown size 9 and it seemed to run small. so i returned them and ordered the supernavy. they fit like my original pair -- correctly and what i would expect from a size 9 shoe. supernavy is the color i was first drawn to (i got the chocolate just 'cause i thought it would be more "normal") so i'm happy with the purchase!
i wear birkenstock clogs and sandals (size 39 narrow) in warm weather, but like the gogh clog for it's softer, squishier sole and warmth in colder weather.