One of the wonderful things about the N9 is the AMOLED screen.
I love reading, and I love reading in the dark.
Using red fontcolor and black background with FBReader doesn't hurt my eyes
and I can read beside my partner who wants to sleep or in a group after nighttime.

But there are some elements which disturb the experience.
If somebody wants to do the same, here is how I solved them.

Disclaimer: Make backups of files you will change and be careful

Problem: Bright statusbar Icons above FBReader.
Solution: Make FBReader fullscreen. Bonus: more text per page!

Edit the file
opt/fbreader/share/zlibrary/declarative/Main.qml
and change the statusbar line so that it reads "showstatusbar: false".

Problem: Bright low power lockscreen clock
Solution: Edit config file

The config file for the lockscreen is here:
/usr/share/themes/base/meegotouch/libsysuid-screenlock-nokia/style/libsysuid-screenlock-nokia.css

In section
LockScreen MLabelStyle#LockScreenLowPowerModeClockLabel
Change color to
color: #FF0000;

If you want to have your standard lockscreen fonts in red to,
you have to replace the other instances of the color white (#ffffff) with red (#ff0000)

Problem: Bright low power lockscreen icons
Solution: Find them and replace them with red ones.

The icons for the low power screen can be found here:
/usr/share/themes/blanco/meegotouch/icons/icon-m-low-power-mode-*
I replaced the battery and silent mode indicators but kept mail and sms notifications in white as they demand my attention.
You can find prepared red icons attached.

Problem: Bright statusbar on lockscreen
Solution: Make icons and font red.

The icons are here:
/usr/share/themes/blanco/meegotouch/icons/icon-s-status-*
Again i kept everything white which may be important

The config file is here:
/usr/share/themes/base/meegotouch/sysuid/style/statusarea.css
You have to change from white to red as above under the key:
MLabelStyle#StatusIndicatorLabelPortrait
This is enough to make the whole lockscreen statusbar red.

You can change other instances of white if you want your normal statusbar in red.

Problem: Bright background image
Solution: Choose a nice one and make it red.

Using gimp:
Load image
Menu->Colors->Colorize
Hue=360
saturation=100
Lightness=-60

place the result somewhere where you can find it from
the background image selector or directly into
/usr/share/backgrounds/

Now you are ready to read in the dark or go stargazing without disturbing your nightvision with your bright phone. Also the red color may help you to sleep faster.