Select by color feature
The Silhouette Studio software (V3.0 and higher) allows you to select images by their line or fill color.
You may go to the Select by Color icon located along the bottom of the software:
This will open a new panel allowing you to either select By Line or By Fill color. Clicking on any displayed color option in the panel will select all applicable images so that they can be moved or grouped together, removed, or otherwise adjusted as may be desired.