How do I add custom colors to a protein sequence?
Select Part of a Protein Sequence

Select the amino acids that will be labeled with a color.
Customize the Sequence Color

Click Edit → Set Amino Acid Color... .

Alternatively, click the "Set amino acid color" menu button in the side toolbar.

Choose the color, then click OK.
Switch Color Modes

If the "Show colors" option is not chosen, a dialog will ask if you would like to display them. Click Yes to show the newly colored sequence.
View the Custom Sequence Colors

The custom sequence colors will be shown in Map and Sequence views.