Method for straightening, conditioning and colouring hair, especially hair with substantial curl

A method for straightening and dyeing keratinous fibers, including the following steps:

• A1) treating the fibers with a straightening agent (G) having a pH of 8.5 to 13.4,
• A2) allowing the straightening agent (G) to act for a period of 30 seconds to 45 minutes,
• A3) rinsing out the straightening agent (G),
• B1) treating the fibers with a conditioner (K) having a pH of 2.0 to 7.5,
• B2) allowing the conditioner (K) to act for a period of 30 seconds to 45 minutes,
• B3) rinsing out the conditioner (K),
• C1) treating the fibers with a coloring agent (F),
• C2) allowing the coloring agent to act for a period of 30 seconds to 45 minutes,
• C3) rinsing out the coloring agent (F),
• wherein the steps are performed in the stated order:
• A1), A2), A3), B1), B2), B3), C1), C2), and C3)
• there is a time interval of 10 seconds to 48 hours between steps A3) and B1) and
• there is a time interval of 10 seconds to 48 hours between steps B3) and C1), and
• wherein
• the straightening agent (G) includes at least one alkalizing agent selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, magnesium hydroxide, calcium hydroxide, and guanidinium hydroxide,
• the conditioner (K) and the coloring agent (F) each include ammonium thiolactate as a reducing agent in a quantity of 2.7 to 5.5% by weight, with the weight indication in each case based on the total weight of the conditioner and of the coloring agent in which the ammonium thiolactate is used,
• the coloring agent (F) includes at least one direct acid dye in an amount of from 0.01 to 5.5% by weight based on the total weight of the coloring agent (F) and has a pH of 1.5 to 6.0,
• wherein the agents (G), (F), and/or conditioner (K) further include a cationic surfactant comprising one or more quaternary imidazoline compounds, and
• wherein the method does not include an oxidation step.