CALC: Background colour can be entered, but no background color appears

Thought this problem is due to my old versiom. Have just installed new version 5.4.2(x64):
Build-ID: f99d75f39f1c57ebdd7ffc5f42867c12031db97a
CPU-Thread 4
OS-Version Windows 6.1
UI Render; Standard
using existing *.XLS files when starting, since I just stated to use calc.
After using the Background Colour button to insert a colour for one or many cells, the entry is accepted.
That can be tested by accessing a different cell and the the cell just modified again:
The menue indicates the previously enterd colour.
Loading existing *.XLS files with many coloured cells (working ok with Windows EXCEL) also shows no colour.
My Question: Is this due to my misuse of CALC or a bug of my system. What must I learn to use CALC correctly,
so that cel background colouring works also with CALC.