Colour schemes applied to structure viewers don't work for nucleotide

As per TODO comment in JalviewJmolBinding.setJalviewColourScheme.
Code tries to construct 'colour' command but only uses peptide residue names.
These don't match the displayed residues (in JMol/Chimera) if the structure is nucleotide.
Example: view 2GIS and use the Jalview Colour menu to Colour Purine/Pyrimidine (or anything else).
Only the 'color white' part of the command takes effect - the model is left entirely white.