Yes, they may turn grey as you get older.
The opposite to gray is gray dark gray is light gray ;)
Gunmetal-gray is considered a dark color. It is a shade of gray that has a slightly metallic finish, giving it a darker and cooler tone.
stress and lack of sleep Some hairs on our body starts to turn gray before the others. You don't say how old you are but the gray hairs starts to come for some people when they are i their 30's.
Dark gray.
Maybe it's because you have very dirty eyebrows
Gray is said to be dark and dismal as in gloomy gray skies
Dark gray to dark brown.
Steve Jobs' eyebrows are black.
Tantalum is a gray, blue-gray, or dark gray metallic element.
Green (very dark green) or Gray ( very dark gray)
Gray dark gray white black red