Method for forming images by a stabilized color intensifying treatment

The process involving color image-formation followed by photographic processing including color developing which comprises contacting an image-wise exposed color photographic element comprising a support having thereon at least one silver halide emulsion layer containing im age-wise distributed silver catalyst nuclei with an intensifying bath containing at least one highly active intensifying agent comprising a halogenous acid or a peroxide in the presence of a reducing agent, which is in a processing bath or the element and in the presence of a color former, and thereby image-wise oxidizing the reducing agent to thereby conduct image intensification through said oxidized reducing agent, the improvement wherein said intensifying bath comprises at least one nitrogen-containing heterocyclic compound having no mercapto group and which possesses an anti-fogging effect, bromide ions in an amount of 1 .times. 10.sup.-4 gram ion/liter or more, and said highly active intensifying agent in an amount of 0.25 mol/liter or more, wherein said nitrogen-containing heterocyclic compound is of the formula:

• ##STR7## wherein Z is a non-metallic group comprising carbon, nitrogen, oxygen, sulfur or selenium, which forms a 5- or 6-membered heterocyclic ring or a heterocyclic ring condensed with a 5- or 6-membered ring, X is an anion other than iodide, A is a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms wherein said substituent is a hydroxyl group, an alkoxy group having 1 to 4 carbon atoms, a carboxy group, or a sulfo group;
• or A is an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or a substituted or unsubstituted aryl group wherein said substituent is a hydroxy group, an alkoxy group having 1 to 4 carbon atoms or alkyl group having 1 to 4 carbon atoms, and B is --(CH.sub.2).sub.n --, --CH.sub.2 O--(CH.sub.2).sub.n --OCH.sub.2 --, ##STR8## or --CH.sub.2 OCH.sub.2 --, wherein n is an integer of 1 to 12.