[High Contrast] "Failed to reload settings" warning isn't legible

[carlos-zamora]

[carlos-zamora]

Did some research:

• The color used is ErrorTextBrush (Color=ThemeResource SystemErrorTextColor)here:

  terminal/src/cascadia/TerminalApp/App.xaml

  Line 44 in 52262b0

  <SolidColorBrush x:Name="ErrorTextBrush"

• We build that message using _BuildErrorRun in TerminalWindow:

  terminal/src/cascadia/TerminalApp/TerminalWindow.cpp

  Line 111 in 52262b0

  auto key = winrt::box_value(L"ErrorTextBrush");

• For whatever reason, SystemErrorTextColor doesn't have a high contrast value, so we just end up using yellow instead.
• I've tried messing with the XAML and I wasn't able to get it to use a theme resource instead. Since we're getting the color via code in TerminalWindow.cpp, we basically have to evaluate which theme dictionary to use at runtime, which makes this a bit more complex.

The good news is, we really only have this kind of illegible text when the Contrast Theme has a light background (i.e. Desert). I'm assigning priority 3 and adding the help-wanted label on it.