Change the "Selected Items" colour for non-focus fields

Question

In Ubuntu 15.10, how does one change the "Selected Items" color for non-focus fields. Here is an example selected line that is coloured brightly when the field has focus:

However, the selected line is almost imperceptible when the field loses focus:

This question is not a dupe of this question which asks about changing the "Selected Items" color for focused fields.

Answer 1

In order to change the Ubuntu theme, both the theme and the Unity Tweak Tool must be installed:

$ sudo aptitude install shimmer-themes unity-tweak-tool

In the Unity Tweak Tool go to Appearance -> Theme and select the new theme. For me, the theme Numix resolved the non-focused Selected Items issue.

This answer is based upon DK Bose's very helpful comments.