A granulated colorant as a granulation product of a powdery nigrosine dye, that has a bulk density of 0.4 to 0.7 g/ml and a hardness of 1 to 20 N. A high-concentration master batch obtained by blending a granulated colorant and a thermoplastic resin, which comprises 25 to 100 parts by weight of a nigrosine dye in the granulated colorant per 100 parts by weight of the thermoplastic resin. A colored composition comprising a granulated colorant or high-concentration master batch and a thermoplastic resin or thermoplastic elastomer.