Oh, nice! The left-hand LEDs on these RJ-45 connectors are bi-colour (green/yellow):
@ve7fim
Pretty standard on 10/100 ports.

@zl2tod

Indeed!

I'm going to be using these for RS-485, with the RED LED indicating termination, green indicating RX, and yellow indicating TX.

@ve7fim @zl2tod so one could read the leds from a distance to decode what’s going on (there’s a paper on that)

@sxpert @zl2tod

I don't connect TX/RX directly the LEDs, but rather drive it from the software stack. That way you can have more control over the blink behaviour and it doesn't leak nearly as much information.