If say a task was due for today, so it will have yellow as the color for color indicator bar. But if the task also has a time and the end time of the task has already passed for today, then the color should change to red, since its overdue now.
If any task is going at present, that is, say if any task was scheduled for today from 9pm to 10pm and its going on at present, then the task should be highlighted/glowing with the accent color as the border color. Example below :