The colour of the optic disc.
D003116:Color; D003124:Colorimetry; D003720:Densitometry; D005654:Fundus Oculi; D005901:Glaucoma / Q000175:diagnosis; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D009900:Optic Nerve / Q000033:anatomy & histology*; D010781:Photography; D013057:Spectrum Analysis
D006454:Hemoglobins