The paper deals with the use of the various color pieces of information for segmenting color images and sequences with mathematical morphology operators. It is divided in four parts. The first one is concerning the choice of the color space suitable for morphological processing. The choice of a connection which induces a specific segmentation is discussed in section 2. Section 3 presents the color segmentation approach which is based on a non-parametric pyramid of watersheds, with a comparative study of different color gradients. In section 4 is introduced another multiscale color segmentation algorithm, relying on the merging of chromatic-achromatic partitionsordered by the saturation component.