This practice-based PhD asks How can a decolonised poster campaign generate a conversation about the production of colonial and racist thinking through the spectacle of publicity and create greater diversity in Mexican Advertising? Hybrid practice-academic methods explore how a multimodal campaign can disrupt the colonial and racist thinking underlying Mexican Advertising. The original contribution is through a decolonial process of researching visual communication, combining ‘practice process’ and academic ‘workshop development,’ mixed with theorised accounts. The Empirical research examines 500 years of 2D visual communication, including the construction of race through Pinturas de Castas that visually categorized peoples in colonial Mexico, to present day outdoor billboards for department store El Palacio De Hierro that is analysed using Visual Semiotics, revealing that this campaign consciously erases certain racial groups representing millions of Mexicans. A theory framework maps the history of key concepts such as Post-colonisation and Decolonisation, with a focus on Latin American theorists Mignolo, Figueroa, Cusicanqui and Boaventura. Five Phases structure the practice part of this PhD. Phase One is a Mexican Communications Review. Phase Two is working with local peoples and sets the groundwork for Phase Three, which is a decolonised visual practice in the form of a multimodal weaponised poster campaign. This is then followed by Phase Four which is a content analysis of the media coverage reaction to observe the industries’ and publics response. Phase Five are the outcomes with the researcher working with the Mexican advertising community searching for solutions. The findings reveal that instead of being a top-down process, advertising practices can be questioned from the bottom up, by taking what Audrey Lorde defines as ‘the master’s tools’ and delinking them through collaboration with local peoples and creating a conversation in the media to remove colonial thinking from branded messages and create greater diversity in Mexican Advertising. This research explores new hybrid practice-academic methods to accelerate change, and it is an original form of altering the Mexican public's understanding of what it means to be Mexican, by showing how colonial thinking can be removed from Mexican publicity practices to resist the racist spectacle through a methodological activism approach. This research in and of itself does not resolve the problem of decolonising but is making a small contribution to this area by creating greater diversity in Mexican Advertising through subversive strategies.