---
id: 5d822fd413a79914d39e993e
title: Part 120
challengeType: 0
isHidden: true
---
## Description
Lastly, in the `:root` selector of the media query, redefine all four of the `--window-color` variables to use `#777`. When you're done, resize the window and watch it go from day to night.
Variables are primarily used with colors, and that's how you used them here. But they can be given any value and used on any property. Your project looks great!
## Instructions
## Tests
```yml
tests:
- text: test-text
testString: const root = code.match(/:root\s*{[\s\S]+?[^}]}/g)[1]; assert(/--window-color1\s*:\s*#777\s*(;|})/g.test(root) && /--window-color2\s*:\s*#777\s*(;|})/g.test(root) && /--window-color3\s*:\s*#777\s*(;|})/g.test(root) && /--window-color4\s*:\s*#777\s*(;|})/g.test(root));
```
## Challenge Seed
```html
freeCodeCamp Skyline Project
```