Compared with blue lakes, green or brown lakes have more algae, sediment and organic matter, says Xiao Yang, a hydrologist at Southern Methodist University in Dallas.

Eyes come in many shades, ranging from dark to light brown, and from green, hazel, and gray, to blue. But despite the many variations that we perceive, there are actually only two different ...

Between 2007 and 2012, lakes tinted with a greenish-brown hue—officially classified as “murky”—stealthily overtook blue lakes to become the country’s dominant lake type, Cara Giaimo ...

An August 2016 Stanford University study published in Acta Ophthalmologica found that "the birth prevalence of iris color was 63 percent brown, 20.8 percent blue, 5.7 percent green/hazel." The ...