, computers.
Note: It was made in a Factorissimo building as the innermost lights were out of range of substations. More signal colour was also used to get the black/grey lights.
The biggest challenge was figuring out how to wire it up with the lights all adjacent to each other, since as far as I can tell that pretty much rules out fancy wiring tricks like in the Sandstorm video. To make things easier, I wrote a program to analyse the gif (after reducing the amount of colours) and detect which pixels either didn't change, or had neighbours with matching patterns that could be wired together. That significantly reduced the amount of combinators required, though the upper middle part was still mostly single lights. It also kept track of which pixel I was working on, its co-ordinates, and what values the constant combinator needed for that pixel.
The actual combinator setup is fairly simple. The constant combinators held the various colour values for each light (or set of lights), using 1 bit per frame. These are then ANDed with the timing signal (2^0 to 2^7, increasing every every 11 in-game frames or so). Since the timing signal gets spat out along with the colours, an extra combinator to neutralise the timing signal is used for lights that need to turn off at some point. That is then fed straight to the lights. Sometimes the signal will use an inactive light as a stepping stone, or one that is always green (since green has the highest priority of the used colours).
Also, yes, they were all placed manually. I suspect a program to spit out some console commands would've worked fine, but I wasn't sure if it would all fit without some manual intervention.
If anyone has any ideas on how to get multiple colour signals to massed adjacent lights without interference, I'd love to hear it.