Just my $.02
Some cockpits and control rooms use low level led lighting to keep the operators eyes from dilating thus giving you better sight and alertness at night. In contrast to the sometimes bright dash, which would make you feel like you're staring into a flash light; causing fatigue. Maybe it counteracts that effect?..
My buddies Mom has a Mazda RX-9 and it has a light exactly like that in Red. I've heard Red and certain shades of green are key. We have red LED lighting underneath a shelf inside our Deer blind here in TX. Helps while getting into it early in the AM, and while it's on, you can still see fairly far out into the brush.
Again, I'm not the guy who decided to put them in, but that's the only practical use I could think of. With exception of the guy who mentioned passing the J back and forth. Comes in handy for that as well!! haha