Hi all!
I am working on a circuit where a 12 chip ws2128b ring is running from an external 5v source which is also powering my board. For the sake of neatness on the PCB it would be preferable to have the 1000uf capacitor on the 5v in rail rather than on the LED out rail. Would this work and still provide protection? In my head it also provides spikes to the board but im not sure if this then translates out to the LED
kindest
sam
1000uF is for decoupling, not filtering.
On a ring, the 5 V and ground each run around the ring and each joins back to itself so there is no "in" and "out" end.
It sounds as if you are making your own ring PCB.
Sorry i have explained this terribly!! I hope the below will help 
Pardon the square representing the ring, the tool i was using had no custom symbols
So in the above the capacitor is on the 5v in connection powering both the board and the ring. Adafruit recommend, as im sure you're aware, putting it between the board and the ring of leds.
As it happens i managed to squish it into the right place anyway so it's a bit of a moot point now, but i did however find a cool circuit diagram website so every cloud !
I hope their actual recommendation is to put the 1 mF capacitor at the connection to the ring of LEDs, rather than interposing wiring resistance between it and the LEDs.
Similarly the resistor in series with the data line should be at the first pixel, though it is not necessary if there is no significant distance between MCU and LEDs and the 5 V line connects to both.
Pleased to see you used the SI notation for the capacitor. 