public void GetLightData(Document document)
{
    // This code demonstrates how to get light information from project and family document
    LightType lightData = null;
    if (document.IsFamilyDocument)
    {
        // In family document, get LightType via LightFamily.GetLightType(int) method. 
        LightFamily lightFamily = LightFamily.GetLightFamily(document);
        for (int index = 0; index < lightFamily.GetNumberOfLightTypes(); index++)
        {
            lightData = lightFamily.GetLightType(index);
        }
    }
    else
    {
        // In family document, get LightType via GetLightTypeFromInstance or GetLightType method.
        // In order to get the light information, please get a light fixture instance first
        FilteredElementCollector collector = new FilteredElementCollector(document);
        collector.OfClass(typeof(FamilyInstance)).OfCategory(BuiltInCategory.OST_LightingFixtures);
        FamilyInstance lightFixture = collector.Cast<FamilyInstance>().First<FamilyInstance>();
        if (lightFixture == null)    // check null reference
            return;

        // Get the LightType for given light fixture
        lightData = LightType.GetLightTypeFromInstance(document, lightFixture.Id);
    }

    // Get the light data via LightType
    Color filterColor = lightData.ColorFilter;  // get the ColorFilter property
    LossFactor lossFactor = lightData.GetLossFactor();  // get the loss factor
    if (lossFactor is AdvancedLossFactor)
    {
        AdvancedLossFactor advancedFactor = lossFactor as AdvancedLossFactor;
        double luminaireValue = advancedFactor.LuminaireDirtDepreciation;
    }
}

Public Sub GetLightData(document As Document)
    ' This code demonstrates how to get light information from project and family document
    Dim lightData As LightType = Nothing
    If document.IsFamilyDocument Then
        ' In family document, get LightType via LightFamily.GetLightType(int) method. 
        Dim lightFamily__1 As LightFamily = LightFamily.GetLightFamily(document)
        For index As Integer = 0 To lightFamily__1.GetNumberOfLightTypes() - 1
            lightData = lightFamily__1.GetLightType(index)
        Next
    Else
        ' In family document, get LightType via GetLightTypeFromInstance or GetLightType method.
        ' In order to get the light information, please get a light fixture instance first
        Dim collector As New FilteredElementCollector(document)
        collector.OfClass(GetType(FamilyInstance)).OfCategory(BuiltInCategory.OST_LightingFixtures)
        Dim lightFixture As FamilyInstance = collector.Cast(Of FamilyInstance)().First()
        If lightFixture Is Nothing Then
            ' check null reference
            Return
        End If

        ' Get the LightType for given light fixture
        lightData = LightType.GetLightTypeFromInstance(document, lightFixture.Id)
    End If

    ' Get the light data via LightType
    Dim filterColor As Color = lightData.ColorFilter
    ' get the ColorFilter property
    Dim lossFactor As LossFactor = lightData.GetLossFactor()
    ' get the loss factor
    If TypeOf lossFactor Is AdvancedLossFactor Then
        Dim advancedFactor As AdvancedLossFactor = TryCast(lossFactor, AdvancedLossFactor)
        Dim luminaireValue As Double = advancedFactor.LuminaireDirtDepreciation
    End If
End Sub