Hi,
Yes, it is possible to change appearance of empty tiles.
1. Create a copy of the default TilePane style
2. Edit the template. There is Visual state <VisualState x:Name="EmptyTile">
Use this code to hide the empty tiles:
<ObjectAnimationUsingKeyFrames BeginTime="00:00:00"
          Storyboard.TargetProperty="Visibility"
          Storyboard.TargetName="RootBorder">
<DiscreteObjectKeyFrame KeyTime="00:00:00.00" Value="Collapsed"/>
</ObjectAnimationUsingKeyFrames>
3. Set this style to the TileView
<igTV:XamWebTileView TilePaneContainerStyle="{StaticResource tpStyle}">
Regards,
Marin