A composition which is configured such that if A500 is the absorbance at 500 nm, B580 is the absorbance at 580 nm and C600 is the absorbance at 600 nm, A500/B580 is 2.0 or more and C600/B580 is 1.5 or more; a color filter; and a hemoglobin sensor which comprises this color filter.本發明提供一種組成物、濾色器及具有上述濾色器之血紅蛋白感測器,該組成物中,若將500nm的吸光度設為A500,將580nm的吸光度設為B580,將600nm的吸光度設為C600,則A500/B580係2.0以上且C600/B580係1.5以上。