What is the best way to demonstrate the complexity of the article/link material on the site?

Question

Design

What is the best way to demonstrate the complexity of the material of an article/link on the website:
1/ color from a certain set (for example, green, yellow, red)
2/ a number on a complexity scale (1-2-3)
3/ another option?
So far, it is planned to put either a color circle or a fraction of complexity (1/3) before the link / title.

Answer 1

The difficulty scale is fine. So does nplus1, for example.

Answer 2

IMHO, the numbers are from 1 to 5, possibly with dorbies, such as Matvey Pravosudov suggests, only 10 is perhaps a bit too much, 5 is closer to the Russian grading system, + the service is usually also roughly rated in stars. I would not recommend colors, it causes a lot of unnecessary / unnecessary associations, for example, red is dangerous, yellow is a warning, etc.