Heritage is in essence dissonant, especially colonial heritage in postcolonial nations. Via questionnaire surveys and interviews, this study investigates Kulangsu in Xiamen, China, a colonial heritage site mainly developed in the 19th and 20th centuries, to unveil the local government’s authorised heritage discourse (AHD) of the site and how tourists perceive the colonial past of Kulangsu and construct their own heritage discourse(s). Results show that, when considering the colonial history of the site, neither the AHD promoted by the authorities nor the tourists’ lay discourses are necessarily negative. However, tension implicitly arises between the tourists’ demand for comprehensive heritage information and the authorities’ selective interpretation of the site. Although the AHD affects lay discourses to some extent, most tourists expect the authorities to present more complete and neutral information about heritage so they can reflect and forge their own conception of colonial legacies. From a critical heritage studies perspective, this tension reflects the power imbalance between the authorities and the tourists and reminds the authorities and heritage experts to rethink heritage tourism and conservation in terms of heritage interpretation. This paper, therefore, calls for additional reflection on the legitimacy of selective interpretation, which implicates a complex process of intricate reasoning that is underpinned by the power imbalance between the authorities and the tourists, ultimately resulting in an AHD.