Read this and answer the question. If the question is unanswerable, say "unanswerable".

Another study from 2012 included 150 dental school students from University of Athens, the result showed that light hair colour (blonde/light ash brown) was predominant in 10.7% of the students. 36% had medium hair colour (Light brown/Medium darkest brown). 32% had darkest brown and 21% black (15.3 off black, 6% midnight black). In conclusion the hair colour of young Greeks are mostly brown, ranging from light to dark brown. with significant minorities having black and blonde hair. The same study also showed that the eye colour of the students was 14.6% blue/green, 28% medium (light brown) and 57.4% dark brown.

What dominant hair color is not believed to be prevalent among Greeks
unanswerable