Ubuntu – Messed menus/labels/buttons/colors after latest update on July 2018

Yesterday I have installed the latest updates for my Ubuntu 16.04.5 LTS, as suggested by the Update Manager. Then I clicked on "Restart later".

This morning the nice surprise:

1. Some application name are no more shown on the launch-menu on the desktop. The icon is ok. I have to go with the mouse over them to make Ubuntu refreshing/repainting them.
2. Some menu names in many applications (Open Office Writer, Calc, etc.) are not shown. Again, I have to roll over the items with the mouse to see the menu item name.
3. Even the the simple GEdit text-editor is messed. If I scroll with the cursor or with the mouse, the suddenly some lines disapperas.
4. Many other faults around the screen (wrong text colors, wrong background color of buttons, etc. etc.)

I use the Xfce desktop manager, but the same happens even with Unity.
Seems something related with everything somehow using text (i.e. menu names, menu item names, labels, button description, etc.

My graphic card:

giulio@ubu:~$ sudo lshw -C display
[sudo] password for giulio: 
  *-display               
       description: VGA compatible controller
       product: GM107 [GeForce GTX 750 Ti]
       vendor: NVIDIA Corporation
       physical id: 0
       bus info: pci@0000:01:00.0
       version: a2
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress vga_controller bus_master cap_list rom
       configuration: driver=nouveau latency=0
       resources: irq:31 memory:fd000000-fdffffff memory:c0000000-cfffffff memory:d0000000-d1ffffff ioport:e000(size=128) memory:fe000000-fe07ffff

Using the PC has become very frustrating and irritating. My productivity has gone down in the cellar…

Any idea?
Maybe it would be better to restore some previous libs? But I get easily lost in executing such tasks. 🙁 🙁

P.S.
Here below there is just an example of the problem:

Here below, the background color of the areas containing text or numbers become transparent and the black color is substituted with red.
Thanks Ubuntu!