Hi,

 I'm developing an application that scan images and search for barcodes. The images are shown in a thumbnailview, i need to highlight the images with barcodes changing the backcolor. Is it possible?

 
Thanks in advance        
 

There is no option to change the background color of individual thumbnails.  The best you would do is select those thumbnails so the selection highlight is drawn under them.

Well, it is possible to render the thumbnails manually by handling the PaintThumbnail event.  Here is a KB with example code for custom painting:  http://www.atalasoft.com/KB/article.aspx?id=10157&cNode=3D8W4P