Appearance
You can customize the appearance of the palettes using the ItemsPanel property:
<telerik:RadColorPaletteView>
<telerik:RadColorPaletteView.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal" />
</ItemsPanelTemplate>
</telerik:RadColorPaletteView.ItemsPanel>
</telerik:RadColorPaletteView>