The Common Teal, usually known as just the Teal in Europe, also called the Eurasian Teal, is native to much of Eurasia. Although sometimes referred to as the Green-winged Teal, that name is usually the North American (sub-) species (Anas carolinensis) which doesn't have the buff border lines on the head or the white horizontal line on the body but has a white vertical line on the side of the breast.

Photos above show the Teal drake in breeding plumage with his "teal green" head and wing markings after which the colour "teal" is named.

Teal pair

The female Teal also has green wing markings (speculum)

In some light/direction the speculum can look almost blue