Any utility to adding grayscale/greyscale to terminal options

[Daniel J S. <dan...@ie...>]

The other day I pointed out the behavior of the "monochrome" option that 
the majority of terminals have in a bug report.  Ethan pointed out the 
legacy nature of it and not knowing how to handle rgb objects under the 
"mono" option.  Right now, it looks like most terminals treat "mono" as 
being a binary color, or single pen color (black).

I'm wondering if it would make sense to add a third option here, 
grayscale.  So most terminals would have:

{color | colour | grayscale | greyscale | monochrome}

Color is obvious, I guess.  Grayscale would map colors to grayscale. 
Monochrome would map colors and grayscale palette to either white or 
black, say a formula for which white is the top "half" of the range and 
black is the bottom half.  E.g.,

rgb 0xff9f00 -> gray 0x8a -> mono 0x1
rgb 0xff6f00 -> gray 0x7a -> mono 0x0

It might be nice having the grayscale option.

The reason that grayscale and monochrome seem useful is that internally 
the terminal may be able to do things to customize the output.  For 
example, postscript might be able to reduce the size of the file if 
grayscale is used as opposed to color.

Dan