The color of menstrual blood is a key indicator of women's health, and while bright red is the most common, it's not the only one. Menstrual blood can range from dark red to brown, black ...

"We have never seen it like this." Residents sound alarm after local river turns concerning color: 'Looks like a stream of ...

The Sarandí canal in Argentina turned blood red last week. Officials suspect a toxic substance used in dyes has entered the ...

A canal in Argentina mysteriously turned bright red on Thursday, alarming residents who were woken up by its strong odor.

There are many examples in nature, including gemstones and paint pigments. Even the color of blood comes from the protein ...

Believe it or not, not all blood is red. The life-giving fluid actually comes in five different colors, depending on what animal you're talking about. The different colors reflect different ...

Argentina's Sarandí Canal turned red after what locals believe was a toxic spill from one of the neighborhood's industrial ...

So why is it so expensive and who's buying horseshoe crab blood? The blue color comes from copper in the blood. But that's not its most interesting feature. The blood contains a special clotting ...

A stream south of the Argentine capital turned a freakish vermilion this week, prompting concerns about pollution. Officials ...