The default EventSpanTopStyle is:

                <Style TargetType="local:EventSpan">

                    <Setter Property="Stroke" Value="{StaticResource BaseBorderBrush}"/>

                    <Setter Property="Fill" Value="{StaticResource BaseBorderBrush}"/>

                    <Setter Property="Template">

                        <Setter.Value>

                            <ControlTemplate TargetType="local:EventSpan">

                                <Grid Margin="0,2,0,2">

                                    <Rectangle RadiusX="5"

                                               RadiusY="5"

                                               Fill="{TemplateBinding Fill}"

                                               Stroke="{TemplateBinding Stroke}"

                                               StrokeThickness="1"

                                               Height="10"

                                               VerticalAlignment="Top" />

                                </Grid>

                            </ControlTemplate>

                        </Setter.Value>

                    </Setter>

                </Style>

The default EventSpanBottomStyle is:

                <Style TargetType="local:EventSpan">

                    <Setter Property="Stroke" Value="{StaticResource BaseBorderBrush}"/>

                    <Setter Property="Fill" Value="{StaticResource BaseBorderBrush}"/>

                    <Setter Property="Template">

                        <Setter.Value>

                            <ControlTemplate TargetType="local:EventSpan">

                                <Grid Margin="0,2,0,2">

                                    <Rectangle RadiusX="5"

                                               RadiusY="5"

                                               Fill="{TemplateBinding Fill}"

                                               Stroke="{TemplateBinding Stroke}"

                                               StrokeThickness="1"

                                               Height="10"

                                               VerticalAlignment="Bottom" />

                                </Grid>

                            </ControlTemplate>

                        </Setter.Value>

                    </Setter>

                </Style>

The default EventPointStyle is:

<Style TargetType="local:EventPoint">

                    <Setter Property="Width" Value="10" />

                    <Setter Property="Stroke" Value="{StaticResource BaseBorderBrush}"/>

                    <Setter Property="Fill" Value="{StaticResource BaseBorderBrush}"/>

                    <Setter Property="Template">

                        <Setter.Value>

                            <ControlTemplate TargetType="local:EventPoint">

                                <Grid Width="{TemplateBinding Width}" Height="{TemplateBinding Width}">

                                    <Ellipse Fill="{TemplateBinding Fill}" Stroke="{TemplateBinding Stroke}" StrokeThickness="1"/>

                                    <Ellipse Stroke="#66FFFFFF" Margin="1,1,1,1"/>

                                </Grid>

                            </ControlTemplate>

                        </Setter.Value>

                    </Setter>

                </Style>

…

<LinearGradientBrush x:Key="BaseBorderBrush" StartPoint="0,0" EndPoint="0,1">

        <LinearGradientBrush.GradientStops>

            <GradientStopCollection>

                <GradientStop Color="#FFa3aeb9" Offset="0"/>

                <GradientStop Color="#FF8399a9" Offset="0.3700000047683716"/>

                <GradientStop Color="#FF718597" Offset="0.3709999918937683"/>

                <GradientStop Color="#FF617584" Offset="1"/>

            </GradientStopCollection>

        </LinearGradientBrush.GradientStops>

    </LinearGradientBrush>