When you head over to the flashlight feature on your Apple Watch, you might have realised that, at some point or another, you're presented with a red light as opposed to a plain white one.
Apple hasn't given a clear explanation as to why this was included, but a red flashlight most definitely has a good purpose.
A bright white light is optimal for emitting the most amount of reflected light in a dark environment, say for example, if you want to illuminate the stairs in front of you at night time. But, having a bright white light isn't always ideal in every situation.
Red light, on the other hand, isn't as strenuous to your eyes in a dark environment as white.
So, having a red flashlight on your Apple Watch is specifically designed for these types of scenarios. Switch on the red flashlight if you wake up to go to the bathroom at night and don't want to wake up someone next to you, or wake yourself up too much from your sleep. It'll also be good to use it if you need light in a movie theatre.
Take a look at the video below by the YouTube channel, Apple Explained, on Why The Apple Watch Has A Red Flightlight...