Can a note card have more than one label?
No it cannot. The label is a special type of information which needs to be singular, because the colour can be used to tint various interface elements, such as the index card “paper”, binder rows, icons and so on. If you need to supply more than one bit of information to a card, look into Keywords. That feature is designed for adding lots of individual things, and you can even show them as colour tabs on index cards, in the View/Corkboard Options/ sub-menu.
UPDATE! I figured out how to change the keyword color – you have to DOUBLE click. Still need to know about the dialogue box.
Thanks! I found the keyword dialogue box. I have two questions: How can I customize the color for each keyword, and can I customize the look of the dialogue box? I don’t see a way to do it from Preferences.
What dialogue box are you referring to; which menu command did you use to bring it up?