Your question is a bit hard to answer as I supplied the word Sharpie, and I'm not sure if this is really part of your question. I believe that the color tan in advertisements is used because it is a universal but neutral color. Tan can be the color of many ethnic groups from Native American to Hispanic to tanned white people. Tan is the color of sand and earth-toned fabric. Now, to use this for a persuasive paper, what do you think tan represents? Try out two or three ideas, write bullet points under each one to see which of the topics is easiest for you to do, and then phrase it as your belief as opposed to other ideas for the color tan. Remember that you are trying to persuade your readers that your view is the correct one. Maybe try to answer what you think their questions about your view might be? Keep referring to your thesis statement and remember to keep proving your interpretation of the color tan.