Two component hair treatment kit comprising a hair coloring cream and a developer composition comprising a specific tensioactive compound

The present invention relates to a kit, preferably for coloring keratin fibers, the kit comprising in spatially separated form at least two kit components: A) a first kit component comprising at least these constituents: at least one alkaline agent; at least one amino acid; at least one organic phosphate ester compound selected from the group consisting of a monoester of a phosphate of one or more alkoxylated fatty alcohols, a diester of a phosphate of one or more non-alkoxylated fatty alcohols, and a mixture of both; water; and optionally at least an oxidative dye; water; and B) a second kit component comprising at least these constituents: at least one emulsifier; hydrogen peroxide; at least one fatty alcohol; and water. The invention relates also to a process of manufacturing a composition which is the second kit component, a composition obtainable by such process, a ready-to-use composition, a way of preparing such and to a use of an emulsifier as in formula (I) and defined above in combination with the organic phosphate ester compound defined above to reduce the viscosity of haircoloring creams.