Prejudicial or preferential treatment of same-race people based solely on their skin tone". Melanism1Tonism2Colourism3Racialism4

The concept you're describing refers to the preferential treatment of individuals of the same race based on their skin tone, which is commonly known as Colorism.

Colorism is a form of discrimination where people are treated differently based on the shade of their skin, often within the same racial or ethnic group. This phenomenon can manifest in various contexts, such as social interactions, media representation, and employment opportunities. It highlights the ways in which beauty standards and social hierarchies can be influenced not only by race but also by the specific tone of an individual's skin.

On the other hand, the other terms you mentioned, such as melanism and tonism, do not accurately describe this concept. Melanism generally refers to an increased amount of black pigmentation in the skin of animals and is not directly related to human social dynamics. Racialism often refers to a broader belief in the superiority of a particular race and is not specifically about skin tone variation within the same race.

Therefore, the correct answer is Colourism (Option 3).