The article focuses on art interventions that were carried out in the Prison in Zagreb, popularly called Remetinec, at the beginning of 2019, with the aim of aestheticizing prison space. It is based on cultural anthropological perspectives, and qualitative ethnographic research conducted in the course of the artistic project organized by the Croatian Association of Artists and led by Melinda Šefčić. The research approaches are grounded in current trends and tendencies in the anthropology of space and place and the anthropology of art. Its objectives are to understand: a) the artistic concept and the creation of art in the prison context, b) the dynamics and meanings triggered by artistic interventions in prison, and c) the ways in which the sense of that specific prison space, as well as the overall perception of the penal system, are being transformed through art. The research centres on the work of four artists who conceptualized and produced their paintings on Remetinec Prison walls. Goran Rakić, Ivan Oštarčević Zgubljen, Dominik Vuković and Slaven Lunar Kosanović have integrated their artwork into well-frequented, communal and joint prison spaces: at the prison entry, along the corridors that lead to meeting rooms, in the therapy room and the courtyard—the locations that are regularly used by different agents (judicial police, members of technical, administrative and expert staff, and prisoners). This allowed the researchers to follow their reactions to the art creation, but also the effects that the interventions had on prison staff and prisoners who used the spaces for their everyday practices (which span from openness to art interventions and the recognition of their potential use for therapeutic purposes, to disapproval and the expressed attitude that artists should respond more directly to the interests of space users). The authors discuss what it means to turn the prison into a site for art and a place of ethnographic research. By doing so, they point to the mainstream perception of prison as a place of isolation, punishment, control and surveillance, which is juxtaposed with the idea of “a colourful prison” represented in this artistic project. In this research, attention is paid to the social, affective, interactive, educational, aestheticizing and therapeutic effects of concrete artistic interventions in a prison. The starting point is the notion that transformative potential of art is not immanent to an artwork. Its agency rather stems from a complex network of diverse social agents, cultural policies, local and global knowledge systems, ways of life, and personal and collective experiences. The emphasis is thus placed on the relations between humans and space, as well as between the people present in prison space, which are established, negotiated and changed by art. By intertwining the issues of prison space-making and art-making, this research poses a novelty in the research of Croatian penal system, which has so far been linked mostly to legal sciences, criminology, education and rehabilitation sciences, social work, psychology and the like. It also enriches the studies of art by emphasising its contextual dimension, by indicating how spatial imageries affect the artistic process and which actions, interactions and reactions are stimulated by the interventions. The main contribution of this cultural anthropological research derives from the capability of ethnography to record and interpret art as a relational and communication-based activity. Such an approach enables the researchers to grasp the mechanisms by which space is changed through its aestheticization, and ways in which space users are becoming more sensitized to change and to facing and questioning the normative expectations from both the prison space and the people in it.