I run NB dev release with the the Dark Metal theme and Fonts & Colors set
to "Norway Today"

Since installing a recent Python build (a few weeks now) any time I restart
NB, it reverts the False / True / None colours to be very dark so that it's
practically unreadable on my background.

The colour it seems to default to is 0,0,102 - and my background is set to
18,30,49. 

I can change the colour to a brighter colour, but it keeps reverting back
if I restart, and I have to repeat the change again.

I don't see any errors when I do the save, but maybe I'm missing something.

It appears to write to the file:

 %APPDATA%\NetBeans\dev\config\Editors\text\x-python\FontsColors\BlueTheme\org-netbeans-modules-editor-settings-CustomFontsColors-tokenColorings.xml

The content:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE fontscolors PUBLIC "-//NetBeans//DTD Editor Fonts and Colors settings 1.1//EN" "http://www.netbeans.org/dtds/EditorFontsColors-1_1.dtd">
<fontscolors>
    <fontcolor foreColor="ff3366cc" name="BUILTIN_FUNCTION"/>
    <fontcolor foreColor="green" name="TRUE">
        <font style="bold"/>
    </fontcolor>
    <fontcolor foreColor="ff9933cc" name="DECORATOR"/>
    <fontcolor foreColor="green" name="FALSE">
        <font style="bold"/>
    </fontcolor>
    <fontcolor foreColor="green" name="NONE">
        <font style="bold"/>
    </fontcolor>
</fontscolors>

which appears to be OK... 

The NB About details are:
  
Product Version: NetBeans IDE Dev (Build javascript2-frameworks-1566-on-20151002)
Java: 1.8.0_60; Java HotSpot(TM) 64-Bit Server VM 25.60-b23
Runtime: Java(TM) SE Runtime Environment 1.8.0_60-b27
System: Windows 8.1 version 6.3 running on amd64; Cp1252; en_IE (nb)
User directory: C:\Users\darrenk\AppData\Roaming\NetBeans\dev
Cache directory: C:\Users\darrenk\AppData\Local\NetBeans\Cache\dev

the Python module version is:

 0.150922