hemochromogen

noun

he·​mo·​chro·​mo·​gen

variants or chiefly British haemochromogen

ˌhē-mō-ˈkrō-mə-ˌjen, -jən 

: a colored compound formed from or related to hemoglobin

especially : a bright red combination of a nitrogen base (as globin or pyridine) with heme compare hemoprotein