Koolies were not bred for looks but for working ability, they come in a variety of colours, which include blue and red merle, solid red, black or grey.
Eyes can be blue, brown, or black.
Sizes range from Kelpie size to Australian Shepherd size. A breed standard is currently being developed - it stipulates that height should be no larger than 550mm males and 500mm for females. History and naming Koolies are also referred to as 'German Koolies', although this name should be avoided because the breed originated in Australia. Its development in Australia is associated with early German and other European immigrant farmers. There are no known Koolie breeds outside of Australia.