I'd better follow up on the somewhat alarming entry I posted from my cell phone earlier: yes, the sky really was green at least to the west and south (it shaded to dark dark blue to the east, as you'd expect for evening twilight), but it wasn't the, ah, fecal-green of an approaching Texas dust storm or the kind of green I've seen associated with tornadoes (with the caveat that I've had extremely limited exposure to tornadoes, but with the reinforcing evidence of local news radio not saying anything alarming during the weather forecast). Rather, it was the freakiest damned sunset I've seen (having captured that title from the heavily pollution-enhanced purple one I watched in Texas a long time ago).
The sky in the direction of the just-set sun was varying shades of blue-green, greenish-blue, and greyish-green, with the narrowest band of rose limning the horizon itself as I started composing that message. (I wrote that on I-95 during pauses in the slow rush-hour traffic (not as bad as a non-holiday weekday at that hour, not even as bad as Saturday's backup, but definitely a lot slower than the times of day I'm usually on the highway, and there was a stretch where things weren't moving much), so it took me several minutes to thumb in instead of the few seconds it would have taken if most of my attention had not been on the much more important task; by the time I sent it the wisp of rose and the aquamarine had gone and there was a lot more of the greyish-green. Given the circumstances, I'm sure those of you willing to excuse my posting it at all will excuse the extremely abbreviated nature of the description I posted at the time.) I checked other directions to make sure my brain hadn't suddenly decided to remap all my colours, and the sky to the east (and by the time I sent that message, even overhead and to the north) was the expected dark, dark blue that it gets as the sunset fades, before it becomes too dark to have colour to it any more.
So ... for all those times when I was a child, when my mother teased me for looking out the window to check when asked what colour the sky was ... and all the times I've heard (or (*cough*) used) the line, "What colour is the sky on your planet?" ... this evening, in Baltimore and between Baltimore and Washington, the sky was green.
A rather pretty, but damned startling collection of greens.