ColorButtonStyle is obsolete property. So I want to use SplitButtonStyle to customize ButtonPart.
When I apply SplitButtonStyle to RadColorPicker it make no difference, but it is ok when I apply this style to SplitButton itself.
Control's version is 2014.1.224.40
Unfortunately you hit a bug in RadColorPicker. From what I tested locally it seems that SplitButtonStyle property doesn't get applied and thus you can't modify the SplitButton this way. Our developers were notified and this will be fixed as soon as possible (for one of our upcomming internal builds released every Monday). An option would be to strip down the whole ColorPicker default template from our themes and modify whatever needed there. There is an article explaining this.
We apologize for the inconvenience. You may find your Telerik points updated as a sign of gratitude for pointing this out.
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