You cannot control specific areas of specific elements via resource washing itself. However our resource washing in WPF works by creating brushes whose keys match the resource keys that are referenced by our styles/templates. So you could find the template whose color you want to change and review it to see what resource keys are referenced. For example you might open the wash base light xaml you are using (e.g. LabelPresenter) from the DefaultStyles xaml (\Infragistics\NetAdvantage 2011.1\WPF\DefaultStyles\DataPresenter\DataPresenterWashBaseLight.xaml) and find the LabelPresenter template. Since it's Background is dynamically linked to the resource key {x:Static igDP:DataPresenterBrushKeys.LabelBackgroundKey}, you might just create a brush whose x:Key is that value and put that in your resources.

If you're unsure what element's template you would need to find to make the change you might use a tool like Snoop to find the element that you want to change and try changing its Background/Fill in Snoop. Once you find the element whose brush is affecting the area you want to change you would look for that element's template in the default xaml.

          <ResourceDictionary>
           <ResourceDictionary.MergedDictionaries>

            <igThemes:DataPresenterWashBaseLight />
            <igThemes:ResourceWasher AutoWash="True" WashColor="LightBlue" WashMode="HueSaturationReplacement">
             <igThemes:ResourceWasher.SourceDictionary>
              <igThemes:DataPresenterWashBaseLightBrushes />
             </igThemes:ResourceWasher.SourceDictionary>
            </igThemes:ResourceWasher>
           </ResourceDictionary.MergedDictionaries>
           <SolidColorBrush Color="Red" x:Key="{x:Static igDP:DataPresenterBrushKeys.LabelBackgroundKey}" />
          </ResourceDictionary>

If the specific area doesn't have a specific brush associated with it or you need to change it otherwise then you would use the style/template from the default styles as a starting point for your own custom template.

ashishkt said:

My question is can resource washing technique is able to change the fundamental properties of the control or this only can give a new color to controls.

 Resource washing is a way to change the brushes used by a theme without having to retemplate the elements. If you need to change other aspects of the visuals used in the default templates then you would need to re-template. When re-templating you have complete control over the look of the elements.

 

ashishkt said:

Also is resource washing better than customizing the controls in terms of memory usage and performance.

There is no simple answer on this. Resource washing is just creating new brushes that are then referenced via dynamic resources so there isn't a lot of overhead to that by itself. If you re-template you could switch to using static resources and you also tailor the template to meet your needs possibly removing elements, animations, etc. that you don't need so you could likely make it more performant but then there are also maintenance considerations. For example if as part of a new feature we need to add/modify the template for an element, if you re-template and you wanted to use that feature after upgrading to the new version you would need to update your template accordingly.