FullCalendar allows you to change the color of all events on the calendar using the eventColoroption. Also you can change text, border and background colors for events in a specific Event Source with event sourceoptions (backgroundColor, color, textColor and borderColor) and for individual events with coloroption, which sets an event's background and border color. Example below demonstrates event colors based on a day of the week.

Events that appear as background highlights can be achieved by setting an Event Object's renderingproperty to background. Background events that are timedwill only be rendered on the time slots in agenda view. Background events that are all-daywill only be rendered in month view or the all-day slots of agenda view. Also the spans of time notoccupied by an event can be colored by setting the renderingproperty to inverse-background.