I have a Phillips 43pus6401 TV set.

The subtitles I get when I play a film from, say, a USB memory stick, are too small for me.

I would like to enlarge them, and change their colour and background.

I was unable to find how to do that,

Any hints?

It would also be nice to change their position and fine-tune their sync, but that's less important.

Thanks,

Dov