Light Fitting to Downlight - Wiring / Wago

It's not a neutral it's switched live, it needs red/Brown sleeeving on it.

 

Hi, I'm only DIY, so ...
The reds are live conductors,
The blacks/Blues are neutral conductors,
The black/Brown wire is the live return from the wall switch, (and NOT a neutral connector) the black wire should be sleeved with a red or brown sleeving to indicate its status.
The Green/Yellow sleeved are earth, please connect these together properly - your life might depend on it one day.

Original wiring might be DIY rather than a professional electrician.

 

Snap

 

Great that you have Wago connectors, various ones even !!

But, you also need an enclosure to put them into - not just stuffed into the ceiling cavity like this connector blocks are (as in millions of homes across the country)

Unlikely you have red/brown sleeving to hand and unlikely your gonna buy 5m when in reality you need 25mm

Either red/brown tape or at least masking tape coloured in with a felt tip

Most important you don’t mix up the single black wire with the others so mark it before doing anything else

Obviously power OFF before touching anything and check circuit is dead and nobody in the house will flick fuse back on without you knowing it (when they find the lights aren’t working)

The Earth cores, and there should be three separate ones there, should be terminated together as simply as the three reds are (which are permanent lives to other rooms)

I’m guessing they’ve been simply twisted together and sleeved over, not great for Earth continuity (hugely important even if your downlight doesn’t require an Earth connection)

So, terminate all three earths outside of downlight by using either a 3 port Wago or the same channel of a connector block. Each one individually sleeved is much nicer also

 

The three existing cables need to be joined in a junction box with another short length of cable connecting that to the new downlight.

An Ashley/hager J501 would be good for this purpose.

Not sure why you have cut out a chunk between the old cable hole and the new light hole. Would have been better to label the cables, disconnect them and pull them through.