Part of the map series created by John George Bartholomew (cartographer) and Harry Hamilton Johnston (author) in A History of the Colonization of Africa by Alien Races, Colonizability of Africa  maps the continent carved into desirable/'healthy' and undesirable/'unhealthy' areas for European colonization.
Originally published in the late nineteenth century, Johnston's work serves as a time capsule into the political context of the colonization of Africa.
Until very recent modern history, mapmaking has exclusively been in the hands of the wealthy, powerful elite. In fact, the European exploration of Asia, Africa, and the Americas is responsible for the early proliferation of cartography in the fifteenth and sixteenth centuries. Maps served purposes beyond simple exploration during this time - mapping was a central tool in colonizing and subjugating 'others,' i.e. non-white non-Europeans. Matthew Edney explicitly states, "Mapmaking was integral to the fiscal, political, and cultural hegemony of Europe's ruling elites" .
Colonizability of Africa exemplifies these power dynamics. Harry Hamilton Johnston, a British explorer and colonial administrator , sees Africa as nothing more than a resource and opportunity to spread European influence. The continent is carved up into different areas of suitability for European preferences with no regard for existing groups, cultures, or land rights.
Johnston's map indicates a complete lack of regard for any existing African borders. Faint lines crisscross the continent, but they are hardly discernible if not actively looked for. The message is clear: the only important demarcations on the map are the discrete groupings of 'healthy' and 'unhealthy' areas. Mapping borders (or intentionally excluding them) is an important tool in asserting territorial rights , which is exactly the intent here.
African input is notably absent in this map - they do not have the power to map themselves and claim land rights. Again, mapping is exclusive to the elite.
Juxtaposing C. Kelso's examples of map styles used to hide or minimize black African settlements as opposed to white ones in Apartheid South Africa , Colonizability of Africa instead highlights cities, ports, rivers, and other natural features and settlements in great detail. The borders between groups of Africans are largely ignored, whereas concentrations of Africans are illuminated.
The purpose of this map is not to prove the superiority of white European settlers; rather, the purpose of this map is to outline where Africa will be most useful and profitable to white European settlers. It is therefore important to list and map all potential resources the continent could provide, as well as potentially hazardous or difficult areas to settle.
Also of note is the accurate scale representation of the African continent.
Many of the most popular maps are in the Mercator projection, which is commonly critiqued for its (outright racist) minimization of Africa, with Western/Europeans areas inflated and the African continent shrunken  *.
Colonizability of Africa flips the script by highlighting the vastness of the continent. In this case, it was important to emphasize the true size of Africa, and therefore its extent of possible colonization and resources.* Tools such as The True Size challenge popular map misconceptions.
Bartholomew utilizes four discrete colors to represent Johnston's four divisions of Africa:
Red represents 'Healthy colonizable Africa.'
Yellow represents 'Fairly healthy Africa.'
Light grey/beige represents 'Unhealthy but exploitable Africa.'
Slate grey represents 'Unhealthy Africa.'
Judith Tyner describes the influence of color on propaganda maps in her work Persuasive Cartography . Every culture has color associations that can be used to shape how viewers read a map.
In Western culture, the color red often represents 'badness' or danger, especially in maps. A first glance at Colonizability of Africa might give the impression that the southern and northern Mediterranean areas of Africa are undesirable danger zones. Bartholomew, however, utilizes red to indicate the best, most desirable (and therefore colonizable) areas of Africa.
Yellow generally has bright, happy connotations (sunshine and flowers and birds, oh my!), but when used in conjunction with red, often takes on a meaning of relativity: if red is bad, yellow or orange is 'less bad' or a warning.
Colonizability of Africa uses yellow in the opposite way: here, yellow is used to describe less desirable but still potentially colonizable areas.
The use of color is interesting because it indicates the opposite of its cultural meaning in the Western world. Even more interesting is considering the symbolism from the African perspective - perhaps African inhabitants would agree that European colonization is bad and dangerous.
The remainder of the continent is defined as unhealthy Africa. Interestingly, Johnston acknowledges the vast natural resources in the area, but states that it is 'impossible for European colonization.'
Similar to Francis Amasa Walker's American Indian Reservation maps from the late 1800s , Johnston and Bartholomew's map serves as a time capsule of the prevailing racism and superiority of colonial Europeans. Africa was nothing more than an opportunity for more land, wealth, and resources for colonizers.
While Johnston's overt racism is jarring in a modern context, it is indicative of a centuries-long global conquest from European powers. Preceding an era of intentionally downplaying black African settlements, Colonizability of Africa is remarkable for its accurate scale and labeling of the continent, which is emblematic of its purpose to define Africa as an untapped resource. It is also notable for its unorthodox use of color, highlighting desirable areas in red and yellow, which are typically used to indicate badness or danger.
 Schomburg Center for Research in Black Culture, Jean Blackwell Hutson Research and Reference Division, The New York Public Library. "Colonizability of Africa" New York Public Library Digital Collections. Accessed June 18, 2020. http://digitalcollections.nypl.org/items/510d47df-fd22-a3d9-e040-e00a18064a99
 Edney, Matthew H. “Cartography Without ‘Progress’: Reinterpreting the Nature and Historical Development of Map Making.” Classics in Cartography, 2011, pp. 305–329., doi:10.1002/9780470669488.ch18.
 “Harry Johnston.” Wikipedia, Wikimedia Foundation, 5 May 2020, en.wikipedia.org/wiki/Harry_Johnston.
 “Keep Out! Absentee Landlords.” No Dig, No Fly, No Go: How Maps Restrict and Control, by Mark S. Monmonier, University of Chicago Press, 2010, pp. 30–69.
 Crampton, Jeremy. “The Power of Maps.” Introducing Human Geographies, by Paul J. Cloke et al., Routledge, 2014, pp. 192–202.
 Kelso, C. "Ideology Of Mapping In Apartheid South Africa." South African Geographical Journal 81, no. 1 (1999): 15-21. doi:10.1080/03736245.1999.9713657.
 Tyner, Judith A. "Persuasive Cartography." Journal of Geography 81, no. 4 (1982).
 Schulten, Susan. "The Cartographic Consolidation of America." In Mapping the Nation: History and Cartography in Nineteenth-century America. Chicago: University of Chicago Press, 2013.
 Johnston, Harry. A history of the colonization of Africa by alien races. Cambridge: University Press, 444-445, doi: https://doi.org/10.5479/sil.792626.39088018043364