The information you're referring to concerns the "OSD" (
on
screen
display) text (
tekst na ekranu).
You can set your preferences for OSD-info under
(rightclick >) Options > Preferences > Video > [OSD]
If you selected "Use new OSD mode (restart required)" you can set "Alpha blending value" to its maximum by drawing the slider to the right.
Note however that when using new OSD mode it has no effect when you're using
any overlay mode for video rendering (under Video > Video rendering).
When you're
not using new OSD mode this slider
(for Alpha Blending Value) only works when you're using VMR/EVR renderers.
However, when
not using new OSD mode you can also select the box "Transparent" (
Providno).
(This box is greyed out and cannot be selected when using new OSD mode.)