This paper presents a new approach to enhance the contrast of color images. The intensity component of Hue, Saturation and Intensity (HSV) color model is fuzzified using Global intensification operator (GINT). A new objective measure called contrast information factor is introduced which is optimized using particle swarm optimization technique to learn the parameters. The enhanced image is evaluated by its entropy, index of fuzziness, contrast information and visual quality factor. Subjective and objective evaluation results clearly show the improvement in the quality of the underexposed images in addition of preserving color and specific image features. Also the shape of the histogram is preserved. The results are also compared with histogram equalization technique.