The short blue Strata-G (SG400) and Fusion matrix rings (FX400) have shorter tips for better engagement with short teeth. The blue ring also grips better in challenging locations such as the distal of the canine or on top of rubber dam clamps. The blue ring is also preferred for pedodontic applications.
The tall orange Strata-G (SG500) and Fusion matrix rings (FX500) have taller tips for proper matrix band adaptation on taller teeth. The orange ring is also designed to stack over top of the blue ring without interference for MOD or multiple tooth restorations.
The green Strata-G (SG600) and Fusion matrix rings (FX600) are for wide preparations where you may be missing a cusp or have an extra wide embrasure to restore where a traditional matrix ring would crumple your matrix band into the prep.