Leg colors on WPC games
Most WPC games have chrome legs. Black legs came on Party Zone, Black Rose, Harley Davidson, Dr. Who, Star Trek: The Next Generation and Corvette (which alone also has black rails and lockdown bar). Creature from the Black Lagoon has near-black gun-metal legs and Road Show blue ones. Gold anodized legs are on Judge Dredd, World Cup Soccer, Flintstones, Indiana Jones and Addams Family Gold.
Systems
Source: Repairing Williams/Bally WPC Pinball Games from 1990 to 1999, Part One, Clay Harrell (pinrepair.com)