Static and interactive objects
You can place this objects on the world with the spacer.exe (for G1) and the spacer2.exe (for G2), or find worlds editors for Union in the community.
light blue - base object
yellow - smart objects - items, npcs, interactive objects
green - specific interactive objects
violet - abstract area objects
oragne - interactive zones
dark gray - visual effects
light gray - helper vobs
red - base triggers
mid blue - triggers with a user callbacks