How to alternate colors for the same css element?

Question

css

Tell me how for one Css element you can alternate different background colors?
I want to alternate, one menu item has a white background with black text, the next item has a black background and white text
.widget.woocommerce li {
background-color: #fff;
color: #000;
}

Answer 1

You can not answer, the solution is just like 2 kopecks.
Google unbanned me.
:nth-child(2n)