The HLS colour space is widely used in image analysis as it is physically intuitive. As the hue component of this space is defined on the unit circle, standard greyscale image analysis operators, specifically morphological operators, are not applicable to it. A variation of the standard morphological operators which require the choice of an origin are discussed. In addition, some lexicographical vector orders, which allow mathematical morphology to be used in the HLS space, are presented. Included in these is a new saturationweighted hue order, which takes hue and saturation into account simultaneously.