They are usually dark gray and thick because they are, or they are about to be, dumping a whole lot of rain.
A cold front brings in cold air. The cold air causes warm air to rise quickly. The rising air forms cumulus clouds. There is often heavy precipitation at a cold front.
A cold front on a weather map is typically depicted by a blue line with triangles pointing in the direction of movement. It represents the boundary of a cold air mass advancing towards warmer air, often causing abrupt changes in weather conditions such as thunderstorms, strong winds, and temperature drops.
If you were to look at it from the front it would look like the diamond shape.
front view
Calligraphy.
Cold sores look like a blister.
they look like your hand like a fist but with the thrum out in front of your fingers.
cold water
From front side it will look like a simple circle
There was no "front" in the Cold War.
warmer than a cold front and colder than a cold front
A stationary front