The invention relates to a hair colouring and/or bleaching composition comprising at least a first aqueous component (i) and a second aqueous component (ii) being mixed prior to application onto hair, wherein the first component (i) or the second component (ii) or both components (i) and (ii) comprise a gel-network system consisting of multi-lamellar sheets and vesicles with d-spacing (interlayer spacing between sheets) between 5 nm and 50nm, preferably 10nm to 30 nm, more preferred 15 nm to 25 nm as measured by Small Angle X-Ray Scattering (SAXS), and the first component (i) or the second component (ii) or both comprise at least a first malodor suppressant being a compound having a distribution coefficient logP of 2 or more and a molecular weight of between 100 and 400, a method for coloring or bleaching hair, a kit comprising the above components and the use of the described hair coloring compoeition for colouring and/or bleaching hair with a reduced or eliminated ammonia odour.
