public class CustomSliderRenderer : SliderRenderer
{
    /// <summary>
    /// Instantiate a CustomSliderRenderer
    /// </summary>
    /// <param name="context">The context to use</param>
    public CustomSliderRenderer(Context context)
        : base(context) { }

    /// <summary>
    /// Called when the Slider changes
    /// </summary>
    /// <param name="e">The details of the change</param>
    protected override void OnElementChanged(ElementChangedEventArgs<Slider> e)
    {
        base.OnElementChanged(e);

        if (!(e.OldElement is null) || e.NewElement is null)
            return;

        // The line colour to the left of the image
        Control.ProgressTintList = ColorStateList.ValueOf(Color.Black.ToAndroid());
        Control.ProgressTintMode = PorterDuff.Mode.SrcIn;

        // The line colour to the right of the image
        Control.ProgressBackgroundTintList = ColorStateList.ValueOf(Color.Black.ToAndroid());
        Control.ProgressBackgroundTintMode = PorterDuff.Mode.SrcIn;
    }

    /// <summary>
    /// Called when the Slider is layed out.
    /// </summary>
    /// <param name="changed">True if the layout has changed, else false</param>
    /// <param name="left">The left of the Slider</param>
    /// <param name="top">The top of the Slider</param>
    /// <param name="right">The right of the Slider</param>
    /// <param name="bottom">The bottom of the Slider</param>
    protected override void OnLayout(bool changed, int left, int top, int right, int bottom)
    {
        base.OnLayout(changed, left, top, right, bottom);

        if (Build.VERSION.SdkInt >= BuildVersionCodes.JellyBean && !(Control is null))
        {
            var thumb = Control.Thumb;

            int thumbTop = Control.Height / 2 - thumb.IntrinsicHeight / 2;

            thumb.SetBounds(thumb.Bounds.Left, thumbTop, thumb.Bounds.Left + thumb.IntrinsicWidth, thumbTop + thumb.IntrinsicHeight);
        }
    }
}

<Slider
                Grid.Row="7"
                Grid.Column="0"
                Grid.ColumnSpan="2"
                x:Name="DaysAbandonedVisible"
                Value="{Binding DaysAbandonedVisible}"
                Maximum="60"
                Minimum="0"
                ThumbImageSource="Slider.png"/>