What are the physical characteristics of a person of Irish ethnicity?
Among the Irish;
43% have dark hair,
35% have medium brown hair,
10% have red and reddish-brown hair,
a minority with light hair.
The eye color is about evenly divided between blue eyes and
mixed eye colour.
About 90% have rather fair skin, 10% have a 'brunet white' skin
tone (in the Midlands). 60% have no freckling at all.
The combination of dark hair and light eyes seems noticeable
Beyond that tall or short, slender or large-framed, etc.
(Figures from a study by Harvard U. "The Physical Anthropology
of Ireland" by E. A. Hooton et al.