Actually, the power rangers casting was re: their outfits was, officially, not intentional. The director, Haim Saban, thought the team needed two girls rather than one like in the original Japanese show, and thought yellow was more "feminine" than the other colors. The original actor cast, a Filipino-American woman, dropped out, and Thuy Trang was next in line. The black ranger actually being black is a little more hazy, but everything I could find indicates that it just wasn't considered before the show aired. Obviously, someone sent them a memo, because in subsequent seasons the colors the next group of actors wore were switched out (i.e., the black guy wore yellow, the Asian guy wore black).
We could perhaps have a discussion about subconscious decisions regarding costuming and race, but I'm thinking it really was unintentional. The Snapple commercial I'm unsure about, but given most commercials simply try to diversify, I could give them the benefit of the doubt.