The Search task pane can't find my clips by their keywords.
First be sure that your clips are actually in the Clip Organizer. Then verify that the keyword you used is actually associated with the clip (click the down arrow next to the clip and choose Preview/Properties to verify the list of keywords). Click Edit Keywords to make keyword modifications if necessary.
You can't recolor BMP, JPG, GIF, or PNG images. Instead, you have to use an external program, such as Microsoft Photo Editor, to convert the color of these images.