Gray zone is usually described as the zone between peace and war. In this zone other states and antagonists try to affect the interests and abilities of a state. The purpose of this study is to identify challenges for collaboration and command and control (C2) in the Gray zone. Further, the purpose also is to identify relevant tools that supports both collaboration and C2 in the Gray zone. The collection of data has been done through literature, one workshop with researchers at FOI, interviews with actors within the crisis management system and by attendance at an international workshop. As a starting point for Gray zone definition and discussion on workshop and interviews a scenario (Typfall 5: Utdragen och eskalerande gråzonsproblematik) has been used. Challenges for collaboration and C2 in the Gray zone has been identified in five areas: (1) Understanding of the Gray zone, (2) Managing activities during Gray zone, (3) Information management during Gray zone, (4) Diligence when managing activities during Gray zone and (5) Organization. The identified tools has been divided in methods and frameworks. The methods are more generic for collaboration and C2. The frameworks are developed specific for Gray zone. The definition of Gray zone and the definitions suitability for managing Gray zone situations should be discussed further. Gary zone could be used for mental preparedness for crisis management actors but are more problematic when analysing and managing the situation itself.