Sample functions and ideas for accessing the R built-in colors. Further examples on converting soil colors to RGB triplets, or for the selection of optimal colors for a thematic map please see the examples linked at the bottom of this page. An excellent discussion on the use of color for presenting scientific data is presented in this paper by Zeileis, Achim and Hornik, Kurt.
Simple Color Display
A Queryable color picker (as suggested by Gabor Grothendieck on the R-help mailing list)
Setup the plot layout, and plot both examples