The present invention discloses methods and kit-of-parts for treating keratinous fibres prior to dyeing to control and modulate dye uptake into the fibre. Organic solvents having log P of from -4.0 to -0.5 or from 0.5 to 4.0 are used to manufacture pre-treatment composition to be applied to the hair. When the hair is pre-treated with at least one organic solvent having a log P of from 0.5 to 4.0 the dye penetration into the keratinous fibres is enhanced, while pre-treating the hair with at least one organic solvent having a log P of from -4.0 to -0.5 reduces the dye uptake. One or more compositions to pre-treat the keratinous fibres can be effortlessly applied on different zones of the hair and can be left in place or removed prior the application of the dyeing composition.