The borders around the color visuals (RadColorPaletteViewItem) in the palette view are shown at the wrong visuals when the MainPaletteItemsSource and MainPaletteColumnsCount properties are changed at runtime.

To work this around, re-adjust the PositionState values of the RadColorPaletteViewItems. For example:

private void ChangePalette()
{
	this.colorSelector.MainPaletteItemsSource = MyGetSourceMethod();
	this.colorSelector.MainPaletteColumnsCount = 10;	
	UpdatePaletteItems();
}

private void UpdatePaletteItems()
{
	var mainPalette = colorSelector.ChildrenOfType<RadColorPaletteView>().First(x => x.Name == "MainPalette");
	var paletteItems = mainPalette.ChildrenOfType<RadColorPaletteViewItem>();
	var paletteItemsCount = paletteItems.Count();
	var columnsCount = mainPalette.PaletteColumnsCount;
	var orientation = mainPalette.PaletteOrientation;

	for (int i = 0; i < paletteItemsCount; i++)
	{
		var paletteItem = paletteItems.ElementAt(i);

		if ((columnsCount == paletteItemsCount) || (paletteItemsCount / columnsCount == 0))
		{
			paletteItem.PositionState = PositionState.Single;
			return;
		}

		if (orientation == Orientation.Horizontal)
		{
			if (i < columnsCount)
			{
				paletteItem.PositionState = PositionState.Top;
			}
			else if (i > (paletteItemsCount - columnsCount - 1))
			{
				paletteItem.PositionState = PositionState.Bottom;
			}
			else
			{
				paletteItem.PositionState = PositionState.Middle;
			}
		}
		else
		{
			if (i % (paletteItemsCount / columnsCount) == 0)
			{
				paletteItem.PositionState = PositionState.Top;
			}
			else if (((i + 1) % (paletteItemsCount / columnsCount)) == 0)
			{
				paletteItem.PositionState = PositionState.Bottom;
			}
			else
			{
				paletteItem.PositionState = PositionState.Middle;
			}
		}
	}
}

A NullReferenceException is thrown when the drop down part of the ColorPicker control is opened initially. For example, this can happen if the IsDropDownOpen property is set to True in XAML. 

This bug is actually related to the RadSplitButton used inside the ControlTemplate of the ColorPicker. It is reproducible also if you use RadSplitButton only. 

The issue reproduces with the Office2016 and Office2019 themes, but probably appears also in other themes (Green and later). The error is gone if you use an older theme like the default Office_Black.

To work this around, set the IsDropDownOpen property of the RadColorPicker in its Loaded event handler.

private void RadColorPicker_Loaded(object sender, RoutedEventArgs e)
{
	var picker = (RadColorPicker)sender;
	picker.IsDropDownOpen = true;
}

Available in LIB version: 2015.2.713

Setting the RadColorPicker's / RadColorSelector's PaletteItemsTemplate has no effect in RecentColorsPaletteView. This is the section which appears when the RecentColors funtionality in the ColorPicker is active.

Available in LIB version: 2015.1.0309

A design time error occurs when the control have a custom style based on the default RadColorPickerStyle. This is reproducible only if the project references NoXaml assemblies and it uses the resource dictionaries with the themes locally (the files are copied in the project and then merged in the Resources).

The error is the following:
'This feature requires service 'Microsoft.Windows.Design.Services.ValueTranslationService' to be present, but it could not be located.	'

As a workaround you can merge the resources directly from the .dll file of the theme as demonstrated in the Setting a Theme help article.
http://www.telerik.com/help/wpf/styling-apperance-implicit-styles-overview.html

Available in LIB version: 2015.1.0604

Set SelectedColor = Red in XAML or code behind or via databinding. Open the color Picker - the red color in Standard Colors is NOT selected but it should be.

A possible workaround could be:

   <Style TargetType="telerik:RadColorPaletteView">
         <Setter Property="SelectedItem" Value="{Binding MediaColor, Mode=OneWay, RelativeSource={RelativeSource AncestorType=telerik:RadColorSelector}}" />
   </Style>


Available in LIB version: 2014.3.1208

RecentColors functionality doesn't work when you set RecentColorsItemsSource. The recent colors are not shown at all but they should be.

When using this property the user should be able to customize the recent colors functionality on his own. Showing the recent colors is a must when setting non-empty colletion via RecentColorsItemSource.

If you bind the SelectedIndex or the SelectedItem properties to your ViewModel and change them from code, the UI will not be updated.
This is both reproducible in ColorPicker, ColorSelector and ColorPaletteView.