Process for dyeing keratin hair fibers comprising the application of a composition comprising a (poly)carbodiimide compound, the application of heat and the application of a composition comprising a (poly)carbodiimide compound

Process for dyeing keratin hair fibers comprising:

• a) the application to the keratin hair fibers of at least one composition C comprising:
• at least one (poly)carbodiimide compound;
• at least one compound comprising at least one carboxylic function;
• and
• at least one colouring agent chosen from pigments, direct dyes and mixtures thereof;
• and then
• b) the application of heat to the keratin hair fibers at a temperature greater than or equal to 30° C.;
• and then
• c) the application to the keratin hair fibers of at least one composition G comprising:
• at least one (poly)carbodiimide compound;
• at least one compound comprising at least one carboxylic function;
• and then
• d) optionally, the application of heat to the keratin hair fibers at a temperature greater than or equal to 30° C.