Multi-step hair dyeing process using at least one titanium salt and a synthetic direct dye

The present invention relates to a multi-step process for dyeing keratin fibres, human keratin fibres such as the hair, in which said fibres are treated with: i) at least one step i) of treating said fibres using a cosmetic composition Ci) comprising a) one or more titanium salts and b) optionally one or more particular carboxylic acids; ii) at least one step of dyeing with a colouring cosmetic composition Cii) comprising c) one or more synthetic direct dyes, preferably chosen from anionic direct dyes; iii) optionally at least one step of intermediate rinsing of said fibres, said step being performed between step i) and ii) or between step ii) and i), depending on the order in which said steps i) and ii) are performed.