I believe that colors are not the most important. Of course, especially for Mandelbrot pictures, shimmering vivid colors are often used, within a range in which hues are moving continuously, with no clashing contrast. However, suppressing these colors makes the bare drawing quite as attractive. The picture structure is the same. The picture remains fascinating because of these details, always the same and always renewed, among which the watcher lingers.
Colors are a bonus.
Daniel Boiteau, a picture of whom will be shown later, proposed an interesting remark. A firm and round cauliflower has a clear fractal structure, with an indisputable self-similarity. Now, to our knowledge, nobody ever sank into unfathomable thoughts in front of this modest vegetable. A cauliflower is simply too common and one hardly sees nobleness in its shapes.