default border color in the dark them
MODIFY
WalletWasabi.Fluent/Styles/Themes/Base.xaml
WalletWasabi.Fluent/Styles/Themes/Base.xaml
<Color x:Key="SystemAccentColorDark3">#FF2E8041</Color>
<Color x:Key="SystemAccentColor">#FF72BD81</Color>
<SolidColorBrush x:Key="TextControlBorderBrushFocused" Color="{StaticResource SystemAccentColor}"/>
- <SolidColorBrush x:Key="TextControlBorderBrush">#33323232</SolidColorBrush>
- <SolidColorBrush x:Key="TextControlBorderBrushPointerOver">#33323232</SolidColorBrush>
<SolidColorBrush x:Key="TextControlErrorBorderBrush">#D85050</SolidColorBrush>
</Styles.Resources>
</Styles>

MODIFY
WalletWasabi.Fluent/Styles/Themes/BaseDark.xaml
WalletWasabi.Fluent/Styles/Themes/BaseDark.xaml
<SolidColorBrush x:Key="TextControlBackgroundFocused">#2F2F2F</SolidColorBrush>
<SolidColorBrush x:Key="TextControlBackgroundPointerOver">#2F2F2F</SolidColorBrush>
<SolidColorBrush x:Key="TextControlForeground">#FFFFFF</SolidColorBrush>
+ <SolidColorBrush x:Key="TextControlBorderBrush">#434343</SolidColorBrush>
+ <SolidColorBrush x:Key="TextControlBorderBrushPointerOver">#434343</SolidColorBrush>
<SolidColorBrush x:Key="StatusBarControlBackground">#191919</SolidColorBrush>
<SolidColorBrush x:Key="StatusBarControlForeground">#A3A3A3</SolidColorBrush>
<SolidColorBrush x:Key="AcrylicFallbackColor">#1F1F1F</SolidColorBrush>

MODIFY
WalletWasabi.Fluent/Styles/Themes/BaseLight.xaml
WalletWasabi.Fluent/Styles/Themes/BaseLight.xaml
<SolidColorBrush x:Key="TextControlBackgroundFocused">#EFEFEF</SolidColorBrush>
<SolidColorBrush x:Key="TextControlBackgroundPointerOver">#EFEFEF</SolidColorBrush>
<SolidColorBrush x:Key="TextControlForeground">#212121</SolidColorBrush>
+ <SolidColorBrush x:Key="TextControlBorderBrush">#33323232</SolidColorBrush>
+ <SolidColorBrush x:Key="TextControlBorderBrushPointerOver">#33323232</SolidColorBrush>
<SolidColorBrush x:Key="StatusBarControlBackground">#ECECEC</SolidColorBrush>
<SolidColorBrush x:Key="StatusBarControlForeground">#777777</SolidColorBrush>
<SolidColorBrush x:Key="AcrylicFallbackColor">#E2E2E2</SolidColorBrush>

default border color in the dark them