A large set of complex datasets require the use of collaborative visualization solutions in order to harness the knowledge and experience of multiple experts. However, be it co-located or distributed, the collaboration process is inherently fragile, as small mistakes in communication or various human aspects can quickly derail it. In this paper, we introduce a novel visualization technique that highlights the group affective tone (GAT), also known as the presence of homogeneous emotional reactions within a group. The goal of our visualization is to improve users’ awareness of GAT, thus fostering a positive group affective tone that has been proven to increase effectiveness and creativity in collaborative scenarios.