Harald Arnkil is a Finnish visual artist, colour researcher and art educator. He studied art and design in England before graduating in 1979 with a diploma (MA) in painting from the School of the Finnish Art Academy (The Academy of Fine Arts).

Arnkil taught art and colour at the Aalto University School of Arts, Design and Architecture, retiring from the position of Senior University Lecturer in Colour Studies in September 2019. Arnkil is currently working on a doctoral thesis on the subject of Colour in the Artistic Process.

Arnkil has published numerous articles and conference papers on colour and its role in art, design and architecture. In the 1980s and ‘90s Arnkil worked alongside his art career as a translator of texts on art, design and architecture from English to Finnish and vice versa. He has also written texts on Finnish artists for exhibition catalogues. His textbook on colour for artists and designers was published in English as Colours in the Visual World by the Aalto University in 2013.

Arnkil is a founder and former president of the Finnish Colour Association (Suomen väriyhdistys), currently serving as its vice-president. He is also a member of the Finnish Painters’ Union, the Helsinki Artists’ Association and a founding member of FLASH, the Finnish Light Art Society Helsinki.