I am using the coefmap plot to display NMF based classification of my data. When I add the sample labels to the plot, it will highlight a colored bar under the classification tree to indicate where data came from. The default colors are difficult to distinguish in presentations (blue, dark purple, light purple). Is there a way to select another color list for the sample labels than the default one? I see there's annColors, but I do not get what parameter type it really is. 

NMF isn't a Bioconductor package. It doesn't appear to be a CRAN package either, being hosted on RForge. So if you have questions, you should email the author/maintainer directly.