Monochrome vs grayscale in scientific journals?
I have a confession to make.  I absolutely ignore it when a publication tells me they want grey-scale or black and white.

Yes, they want it because somebody is going to put something on some dead trees, they're going to be cheap about it and not use color, and somebody might actually pick up a dead tree and see my mangled image.  But either they're also going to put it in a PDF, or else I'm going to put a pre-print in a PDF and that PDF is going to go online in all its radiant rainbow glory, and that is what people will actually read.

So [CENSORED] monochrome.  That is so 20th century.