Dark blue: Nice dinner/lunch in ‘quiet’ places. Often need reservation.
Red: Bars/Cafés. Go for drinks, nice places in the evening (i.e., sunset on a roof-terrasse) or later at night. Some of them also have a dinner-menu option.
Green: Tapas. Typically crowded places. Go to one of them, have a small drink and a small dish and move to the next one ;). Good for lunch time, or to have something before a paella.