When FWRK ignites it uses DUST to create all the colours. It uses the ctype variable to store some information (I don't know what exactly but it seems to have nothing to do with the colour). Maybe, after the lifespan of DUST turns back to whatever is stored in the ctype variable. Or maybe the ctype variable is used for direct interaction.
@Catelite(View Post) is correct. When FWRK explodes, it turns into dust. One of the variables (tmp) used to store the dust colour is the same as the one used to make H2/O2 turn into water when burnt. When the dust is set on fire, that variable does not get reset, so the fire sometimes later turns into water vapour.
Fixed.
(Edit @Thecool(View Post) : fixed for next version. The only things that get released immediately are fixes for very major bugs/crashes)
While trying I found another glitch. when I flood fill with NEUT (while puased) as I moced my mouse down, the neut came down as if I were pulling down blinds.
If you are talking about the seemingly row-by-row flood fill/partial flood fill, i think I know what you are talking about and have experienced it myself