A nice touch is that the 2 pack lets you keep one relay in a tool kit.
Mini Micro PCB Panel Slide Switch Assorted Kit 2/3/4 Pin for Arduino DIY
You will find that the black color resists showing dust and smudges better than lighter options over time.
Because it is black, the relay looks uniform when you group several units together in a row.
These general purpose relays show up a simple black unit, which keeps the overall appearance tidy and consistent.
You will find that the CSJ-38-70010 behaves reliably in hobby projects and small control boxes.
The black color gives it a neutral presence that doesn't fight with your wire colors or labels.
You will find that the black finish helps keep the setup looking tidy even in busy cabinets.
If you prefer a low profile look, the black color should make it easy to integrate without clashing.
What stands out about this relay is the black color, which gives it a professional and understated look on the board.
You will find that the TE brand is stamped neatly, which gives a sense of care.