Interference films with gold, red, blue or green color have been successfully produced on stainless steel at room temperature by applying the triangular current scan method. The anodic current scan over the transpassive region led to the forced dissolution of the steel, and the cathodic current on the reverse scan attributed to the reduction of chromate (VI) to Cr3+. The metal ions generated by both reactions were hydrolyzed to form an interference film. The thickness (coloration) of the interference film depended linearly on the electrolysis time and the logarithm of the space between the two triangular waves.