Some random colors (on the left) are clustered according to the Euclidean distance of their corresponding RGB vectors. The image on the right shows the result of the process. Reload the page to create different colors.
In both cases, a Gosper Displacement is used for compactness. Because of this displacement, clusters can be appreciated as contiguous regions of cells having similar colors.
Clustering is provided by the hierarchical clustering feature of the clusterfck library.