I’ve been 40 years discovering that the queen of all colors was black.

-Pierre-Auguste Renoir

You can wear black at any time. You can wear it at any age. You may wear it for almost any occasion.

-Christian Dior

Black is the quintessence of simplicity and elegance.

-Gianni Versace

It is undeniable that there is a large variety of tops. The top styles are much more than pant styles, and the design differences from tops to pants include prints, colors, and patterns. I can give some typical examples of pants:

1. Dark-colored pants: black and navy pants.
2. Brightly-colored pants: orange, red, yellow, and green pants.
3. White, Blue, brown, gray, khaki pants.
4. Printed pants: for instance, floral print leggings, polka dot pants.

However, in reality, single color, especially black, blue (blue jeans), and navy pants are mostly worn. Many people find it difficult and uncomfortable to mix brightly-colored and printed pants with other items.
Therefore, it can be inferred from this point that there are a limited number of pants to pair with a greater number of tops. This also means that we can have different kinds of tops to go with a particular pair of pants.
What is the most popular color in men and women’s pants in the world today, black, blue (blue jeans), or navy?
My answer is black. You may think: “It must be blue. Thousands of people like wearing blue jeans everyday.”