The Ocean Colour Thematic Assembly Centre (OCTAC) builds and operates the European Ocean Colour Service for the Copernicus Marine Environment Monitoring Service (CMEMS) providing global, pan-European and regional (Atlantic, Arctic, Baltic, Mediterranean, and Black Seas) ocean colour products. This project is related to co-operation in the Baltic Sea ocean colour product development and validation. SYKE provides validation datasets, participates in product validation and gives Baltic Sea assessment expertise.