In this paper we present some methods for indexing and segmenting colour images. The proposed procedures are based on well-known algorithms, but now we use digital distance functions generated by neighbourhood sequences to measure distance between colours. The application of such distance functions is quite natural and descriptive, since the colour coordinates of the pixels are non-negative integers. An additional interesting property of neighbourhood sequences that they do not generate metric in general, so we can obtain many distance functions in this way. We describe our methods for RGB images in details, but other image representations also could be considered. Moreover, the proposed methods can be applied in arbitrary dimensions without any difficulties.