Hello Pavel, 

Thank you for posting in our forum. 

The WebUpload doesn’t share the same presets as the WebImageButton. In fact it’s client side implementation is based on the igUpload widget. As such it has a different theming structure than the WebImageButton.

It uses the themes which are added by default in the  <AppRoot>/ig_ui/css/themes folder when you add the WebUpload control to your page. Depending on which theme is referenced on the page the upload button will appear different. 

Unfortunately we do not provide a theme that looks similar to the Macintosh preset for the igUpload, however our IgniteUI controls support jQueryUI themes as well as Bootstrap themes which you can additionally modify  to achieve a similar look.

For more details on the theming you can refer to the following topics:

http://www.igniteui.com/help/deployment-guide-styling-and-theming#_Using_Theme_Roller

http://www.igniteui.com/help/deployment-guide-styling-and-theming#Using_Bootstrap_Theme_Generator

 Another options is to modify the classes directly in the related infragistics.theme.css folder or overwrite them in the your page in order to change the look of the control. You can find a full list of the classes names and what they’ll affect here: http://help.infragistics.com/jQuery/2015.2/ui.igupload#theming

 Let me know if you have any questions. 

Best Regards,

Maya Kirova

Infragistics, Inc.

http://es.infragistics.com/support