easier definition of single colour regions, or creation of user colourschemes for symbol classes

Often, its desired to apply a single colour to a region of an alignment. its often convenient for these colours to be treated as a residue colourscheme - allowing specific residues to be excluded. Eg
danhitchcock at neo.tamu.edu:
3. Improve custom color. One specific feature would be to assign multiple amino acids a single color at the same time. For example, I made a custom color for labeling certain beta strands called "yellow." Basically everything is yellow except for histidines. TO make this, I had to click on each amino acid and then click on the yellow color which was somewhat tedious. It would have been nice to select everything and define it as yellow and then histidines as blue.