How do I wire my new ceiling light?
What you call brown is actually "white".

Likely black/red carries mains power.
White/red is a leg down to the switch. L is Load. E is Earth.
Your bulb should span from the black (neutral), to white (switched hot).

You can verify this all with an inexpensive non-contact voltage tester.
See also https://diy.stackexchange.com/a/28019/5960