Disregarding the pendant drop itself, the ‘new colours’ cable looks to be an extension taking a permanently live feed to another fitting or accessory. They could also conceivably be a new feed to the entire lighting circuit but that is less likely.
Either way, it’s best thought of as a normal ceiling rose with an extra loop in/out.
Same principals as usual - identify the switch wire, set that aside, then all remaining neutrals together, all remaining lives together, fitting connected to the neutrals and one side of the switch wire, other side of switch wire to the lives.
As above you’ll need an extra wago or other connector for the permanent lives, a 5 way wago would probably be easiest for this one.