Kaposi sarcoma in darker-skinned individuals can appear as dark purple, brown, or black lesions on the skin or mucous membranes, which may blend with natural skin tone and be harder to detect early. It is commonly associated with HIV/AIDS or immunosuppression, and can affect internal organs in more advanced cases, leading to more serious complications. Treatment includes highly active antiretroviral therapy (HAART) to manage HIV, as well as chemotherapy, radiation therapy, or immunotherapy to target the cancerous lesions.