How to fix the problem of drop-down menus being transparent and not readable in Kubuntu 15.10

Question

The Problem: The task manager dropdown menus are all transparent and not readable at all. The same goes for all the dropdown menus of libre office. I have tried to change the desktop theme but the transparency kept on appearing on all those menus hindering me from reading them. Disabling all the effects of the desktop (ALT + Shift + F12) did not help at all as well.

Objective: I need to remove all the opacity and transparency of those menus. I simply need a clear readable desktop environment.

Any suggestions, comments or solutions will be greatly appreciated.

Note: I am using Kubuntu 15.10 (Not a fresh installation. I have just installed the KDE desktop environment on top of the Ubuntu Mate 15.10 then decided to use it as my default.

Answer 1

Head to

System Settings > Workspace Theme > Desktop Theme > Theme

Choose style you like, Oxygen seems to be darkest

Answer 2

In my case it was the Application Colour Scheme in: Settings -> Appearance -> Colour.

Change the Theme with a Darker one and see how it goes. My menus were white and my theme dark so no menus were visible when I click on a drop-down menu.