90650 Heavy Duty 12-Volt LED Flasher, 2 Terminals, 2-Pin LED Flasher, 12V, 20Amp

You will find that the black color resists showing dust and smudges better than lighter options over time.

You will find that the black color makes it easier to match with other black connectors and terminals.

Because it is black, the relay looks uniform when you group several units together in a row.

I noticed the black housing looks clean on the rack and doesn't catch light in distracting ways.