Changing colors to navigation and to slide widget

[SueB]

Getting stuck on this color stuff sometimes. Am I able to change the text color for the Navigation bar, and if I can, how?

Attaching a picture to show which one I am speaking of.

Also on the widget for the slider, can I change the overlay color (it's gray now) to something else and if so, how?

The number selector on the widget, it's gray and white, can I change that color too?

Thanks for all your help...I feel that I am sometimes less than smart...but you all are helping me to learn!
Sue