[Libreoffice-ux-advise] input on changing definition of "dark" colour for fdo#61993

Hi,

I'm looking for input on a proposed fix for a doc compatibility issue 
(fdo#61993, patch: https://gerrit.libreoffice.org/2601)

In Writer when a font colour is set to "automatic" (which is the 
default), it will be set to black or white depending on whether the 
background is "dark".

Microsoft Word does the same thing, except it has a different idea about 
what background colours are considered to be "dark".  This leads to 
compatibility problems when importing and exporting doc/docx file formats.

My tentative proposal was to change LibreOffice's definition of "dark" 
to match Microsoft Office more closely.

Specifically a colour would be considered "dark" if its luminence is <= 
60 (on a scale from 0 to 255).  Currently it is considered "dark" if its 
luminence is <= 38.

Putting aside questions of compatibility, I think this does actually 
produce a visually better result.

What do you think?

Another perhaps separate issue is that the code which decides whether a 
colour is dark is used for a number of different purposes, not just for 
word processor documents.  For example I see a calls to it from VCL code 
relating to user interface themes.  How scary is it to change the 
definition of "dark" across the whole application?

Regards,
Luke.