The electrically held snaplink relay, depending on when it was manufactured, can be either white or black for the same exact relay module. They are the same interchangeable part. A simple way to identify them is to check if the relay on the circuit board is shaped like the T.
"Electrically Held Relays" cannot be installed or used with Relay Panels built for "Mechanically Held Relays" or vice versa, because both require different circuitry to drive them.
20 AMP Relay
30 AMP Latching