Two themes, and one place that decides what colour a station is

Colours came from static brushes scattered over the windows. They now come
from a Theme, and everything that paints a station, a spot or a log row
asks Themes.Current as it paints, so changing the theme changes every
window without reopening it.

light is N1MM's own palette, read out of ApplicationStyles: the pale blue
behind a window, ivory on a button, white boxes, and the four colours a
station is painted in. dark is the same states in colours for a dark
screen, which is roughly what the program looked like before.

Config > Manage Skins, Colors and Fonts picks one, under N1MM's name for
the same dialog, and shows what each theme paints a callsign. The choice
is kept in settings.json as Theme, and light is the default.

The window chrome follows through resources the Fluent controls read, so a
text box and a button take the theme's colours in every state. Fonts and
skins are not part of it.

Looked at under Xvfb in both themes: the entry window, the theme dialog,
and the log window with its rows still coloured by what each contact was
worth.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/Nonemm.App/App.axaml

@@ -1,11 +1,27 @@
 <Application xmlns="https://github.com/avaloniaui"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              x:Class="Nonemm.App.App"
-             RequestedThemeVariant="Default">
-             <!-- "Default" ThemeVariant follows system theme variant. "Dark" or "Light" are other available options. -->
+             RequestedThemeVariant="Light">
+    <!-- the colours behind these keys are filled in from the theme in use, in
+         App.ApplyTheme -->
+    <Application.Resources>
+        <SolidColorBrush x:Key="FormBackground">#CDDAEB</SolidColorBrush>
+        <SolidColorBrush x:Key="FormForeground">#000000</SolidColorBrush>
+        <SolidColorBrush x:Key="ButtonBackground">#FFFAF0</SolidColorBrush>
+        <SolidColorBrush x:Key="FieldBackground">#FFFFFF</SolidColorBrush>
+        <SolidColorBrush x:Key="FieldForeground">#000000</SolidColorBrush>
+    </Application.Resources>
 
     <Application.Styles>
         <FluentTheme />
         <StyleInclude Source="avares://Avalonia.Controls.DataGrid/Themes/Fluent.xaml" />
+
+        <Style Selector="Window">
+            <Setter Property="Background" Value="{DynamicResource FormBackground}" />
+            <Setter Property="Foreground" Value="{DynamicResource FormForeground}" />
+        </Style>
+        <Style Selector="Menu">
+            <Setter Property="Background" Value="{DynamicResource FormBackground}" />
+        </Style>
     </Application.Styles>
-</Application>
+</Application>