I support your right to put on make-up (and then make fun of you). However, your last sentence is silly. People do not think "black is intrinsically offensive". People think that due to the long history of white people caricaturing black people by putting on blackface, blackface is offensive. You may want to put on black makeup in a context-free way, but others may be more aware of context and have a different reaction. That may be their problem, depending on your views on what steps to take others into account are appropriate.