In this paper, a new adaptive filter intended for the attenuation of impulse noise in color images is proposed. The new filtering design is based on the concept of a peer group of pixels sharing similar chromatic properties. The novel approach adaptively determines the size of the peer group which minimizes the aggregated distance to the peer group members, utilizing the Fisher linear discriminant. The analysis of the obtained noise reduction results leads to the conclusion that the new filter is capable of reducing even strong impulse noise, while preserving and even enhancing the edges of color images. This unique property of the proposed filtering design is shown on examples of color biomedical images.