How to change bar color?

Is there any way to change the bar color? I tried durationBarColor attribute, but it's not working. Thank you.

var e = new DayPilot.Event({
start: new DayPilot.Date(dt+availabilitySet[j].start),
end: new DayPilot.Date(dt+availabilitySet[j].end),
id: availabilitySet[j].id,
text: response['data'][i].name,
durationBarColor: "red"
});