A method of preparing a homogeneous, ready to use, sulfate-free,
single-part color developing composition comprises the steps of:
A) mixing in water, a color developing agent present as a sulfate salt,
an antioxidant for the color developing agent, alkali metal ions in at least
stoichiometric proportion to the sulfate salt, and a water-miscible or water-soluble,
straight-chain organic solvent having a molecular weight of from 50 to 200, and
present at a concentration such that the weight ratio of water to the solvent is from
15:85 to 50:50, to form an alkali metal sulfate in the solution, and B) removing the alkali metal sulfate from the solution.