Black and white smoke?

[KDR_11k]

The emit-sfx command has SFXTYPE_BLACKSMOKE and SFXTYPE_WHITESMOKE available as options but both seem to do the same in Spring, can we change that so SFXTYPE_WHITESMOKE emits the current smoke and SFXTYPE_BLACKSMOKE emits a very dark smoke? Could just be a normal smoke sprite darkened to 10% brightness or something.

[Gnomre]

It'd be nice if we could emit missile-style smoke too as contrails

[Crampman]

It would be nice if we couls use customs sfx-stuff.
Things like beams, sprites, particles...