The color of the top menu bar of the MacBook Air is usually determined by the desktop background color or wallpaper you choose. If you want to change the color of the top menu bar, consider changing the desktop background or wallpaper.

Here are the steps to change the desktop background or wallpaper:

Click on the blank space on the desktop, and then click? In the menu bar. Icon.

Select System Preferences, and then click Desktop and Screen Saver.

In the sidebar on the left, select the desktop whose background or wallpaper you want to change.

You can select a new background or wallpaper in the window on the right. You can choose one of the options provided by Apple, or click the+button to add your own picture.

After selecting the new background or wallpaper you want, you should immediately see that the color of the top menu bar has changed.

Please note that some desktop backgrounds or wallpapers may be similar in color to icons in some applications, which may make the text and icons in the menu bar illegible. You can try to change the background or wallpaper to find colors and patterns that are more suitable for your needs.

Or go to System Preferences and click General to change the appearance to light, dark or automatic.