Costume design in CATWS: Nick Fury, Black Widow, and SHIELD.
Marvel Studios obviously had to keep Back Widow’s red hair for the movies, but instead of going for a natural shade like Pepper Potts, they went for a bright red tone that could only come from a bottle. That’s where my comparison with Nick Fury comes in. I think that Black Widow purposefully dyes her hair such a noticeable shade because it then becomes her defining feature.
The result? As soon as she changes her hair colour to something else, she can easily slip under the radar. A reverse disguise like Nick Fury’s carefully constructed image as a leather-wearing badass, which allowed him to disappear just by putting on a hoodie and sunglasses instead.