original composition for multicolored tissue preparations including ponceau de xylidine, acid fuchsin, iron alum hematoxylin, and either aniline blue or fast green FCF; chromatin stains black, cytoplasm is in shades of red, granules of eosinophils and mast cells are deep red, erythrocytes are black, elastic fibers are red, and collagen fibers and mucus are dark blue (aniline blue) or green (fast green FCF); modifications substitute other dyes, such as Biebrich scarlet red and wool green stain.