The 5600 G Shock blue is a relative concept both as to color and design. Here are three models that differ significatly both in their blueness and in their design twirks.
From left to right, a 2001 DW-5600GF2 FRF Series, a 2007 DW-5600GM-2 Metallix-G and a 2000 DW-5600BD-2JR Haaken. As you can see, we have a jelly, a metallic and a solid blue. White face, stealth black face and standard black face. Illuminator, Water Resist and Foxfire text.
Keepers are clear jelly, black and blue.
Metal bits and pieces more or less identical.
Different plastics evident from straps.