I have two A500's the first is an early one (serial number about 34000), KS1.3 and green/red LED's. Made in far east.
The other is S/N something like 950,000, KS 1.3, green/orange LED's and is made in West Germany.
Unless this is a red herring it seems like later models have the green/orange LED's. The motherboard in the later one is a couple of revisions higher and has quite a few visible differences. Unfortunately it also has a duff op-amp on one of the audio-outs, so I still use the old a500