A hair dye composition comprising the following components (A) and (B), in which the mass ratio of the component (B) to the component (A), (B)/(A), in a whole composition is 1 or more and 100 or less and the pH (25° C.) during application is 7.5 to 12:(A): one or more azo dyes selected from the group consisting of the following (A-1), (A-2) and (A-3):(B): at least one member selected from the group consisting of guanidine carbonate, guanidine hydrogen carbonate, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate and lithium carbonate.