Changing highlight color on upcoming event in upcoming calendar widget

I would like to change the color of the event date in the upcoming calendar widget as I can't see a difference and don't even know if there is a date scheduled.

I found 2 threads that addressed this, tried the css on the one thread and it did not work. There is no answer on the other one.

Here is page to show you with a calendar entry for March 4, 2017 so you can see the problem:

I refer to the calendar widget and the color I want March 4th to be is #dd3333

However, I want this to apply to any date that is listed. I have also enabled support access and thanks in advance for your help. Linda iempoweru