[jackie_w]

With a lot of help from NiLuJe we finally got this working. I'm going to document it here in case anyone else is interested.

Method A: Miniclock's foreground/background colours automatically match those currently being used by the rest of the screen.

1. In the NightMode config file (.kobo/nightmode.ini) you must enable the retainStateOverRestart option in the [state] section
   

   [state]
   retainStateOverRestart = yes	# yes / no

   This is necessary so that the Miniclock hack will be able to tell whether your Kobo is currently displaying white-on-black or black-on-white.
   
2. In the Miniclock config file (.addons/Miniclock/miniclock.cfg) leave the foreground/background colours at default
   

   fg_color=BLACK
   bg_color=WHITE

3. Using the code below, customise the file usr/local/miniClock/miniclock.sh and replace it in KoboRoot.tgz
   
   Manually change the default code
   
   Spoiler:

   update() {
       sleep 0.1
       fbink -X "$cfg_offset_x" -Y "$cfg_offset_y" -F "$cfg_font" -S "$cfg_size" \
             -C "$cfg_fg_color" -B "$cfg_bg_color" \
             "$(date +"$cfg_format")"
   }

   
   to this
   
   Spoiler:

   update() {
       sleep 0.1
       if grep -q "invertActive\s*=\s*yes" "/mnt/onboard/.kobo/nightmode.ini" ; then
           fbink -h -X "$cfg_offset_x" -Y "$cfg_offset_y" -F "$cfg_font" -S "$cfg_size" \
             -C "$cfg_fg_color" -B "$cfg_bg_color" \
             "$(date +"$cfg_format")"
       else
           fbink -X "$cfg_offset_x" -Y "$cfg_offset_y" -F "$cfg_font" -S "$cfg_size" \
             -C "$cfg_fg_color" -B "$cfg_bg_color" \
             "$(date +"$cfg_format")"
       fi
   }

   
   
4. Reinstall the Miniclock hack using the newly customised KoboRoot.tgz. I think this will automatically cause a full reboot, which is necessary for the NightMode hack to detect the change made in step 1.

I also offer this as a slight variation ...

Method B: Miniclock will always display its time/date text in a more muted mid-grey. Its background will automatically match that currently being used by the rest of the screen.

1. Same as Method A
2. Same as Method A, but choose one of the mid-greys for foreground color, e.g.
   

   fg_color=GRAY7

3. Same as Method A, but use this as the replacement code instead
   
   Spoiler:

   update() {
       sleep 0.1
       if grep -q "invertActive\s*=\s*yes" "/mnt/onboard/.kobo/nightmode.ini" ; then
           fbink -X "$cfg_offset_x" -Y "$cfg_offset_y" -F "$cfg_font" -S "$cfg_size" \
             -C "$cfg_fg_color" -B "BLACK" \
             "$(date +"$cfg_format")"
       else
           fbink -X "$cfg_offset_x" -Y "$cfg_offset_y" -F "$cfg_font" -S "$cfg_size" \
             -C "$cfg_fg_color" -B "WHITE" \
             "$(date +"$cfg_format")"
       fi
   }

4. Same as Method A

And finally ... I think Methods A and B could probably be combined to auto-detect what the user wanted based on the config's fg_color setting. However, as my shell scripting skills are practically non-existent, I'll leave that for someone else to consider.