sharee.bike-App/TINKLib/View/Themes/Konrad.xaml

<?xml version="1.0" encoding="utf-8" ?>
<ResourceDictionary xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="TINK.Themes.Konrad">
    <!-- Pallete -->
    <!-- Red #ff0000 -->
    <Color x:Key="primary-back-title-color">Red</Color>
    <!-- Pallete-end -->
    <Style ApplyToDerivedTypes="true" TargetType="NavigationPage">
        <Setter Property="BarBackgroundColor" Value="{DynamicResource Key=primary-back-title-color}"/>
    </Style>
</ResourceDictionary>