Set scheduler timeline view events background color from start time of first event to end time of last event

[Coolasia]

Hi all,

I have an issue with scheduler timeline view.
As I mentioned in title, I would like to add background color all the way from start time of first event to end time of last event as the attached image.
And also, I want to set different color based on time range in same event.
How could I do that?

Thanks,
Lin