Why is it probably not a good idea to wear black clothes while walking along a road at night?

For one thing it's night and you're wearing black lol also wearing dark colors of such and walking down a road is dangerous due to drivers not being able to see you as well a they could during the day. Let's say a driver when needs glasses is driving and they're kind of hugging the line and don't see you. They could simply overlook you and hit and severely hurt or even kill you, and same goes with drunk and drivers that are tired and haven't got the right amount of sleep. It's like wearing a meat suit in a tigers cage, it's not the brightest thing to do!

Wavelength divides in half and speed stays the same.