Today, Mytour will guide you through the steps to change the workspace background color in Adobe Illustrator.
Steps

Open the Adobe Illustrator file. To start, double-click the yellow app icon with the 'Ai' symbol. Then, click on File in the top menu bar and select Open…. Choose the file you want to change the background color for and click Open.

Click on File
in the menu bar.

Click on the Document Setup… option. This option is located near the bottom of the menu.

Tick the checkbox for Simulate Colored Paper. You will find this option in the 'Transparency' section of the dialog box.

Click on the color sample displayed above. This sample is located on the right side of the 'Transparency' section, just to the left of the checkerboard pattern.

Pick the color you wish to set as the background. You can do this by clicking on the color wheel and adjusting the shade using the slider.

Click and drag the color sample into the empty square. The empty squares to the right of the color sample are where you can save your custom colors.

Close the dialog box by clicking the X button (Windows) or the red dot in the top corner of the dialog box (Mac).

Click on the color sample below. It is located to the right of the 'Transparency' section, just left of the checkerboard pattern.

Click on the color you wish to save. This color will appear in the small square at the bottom-right of the dialog box, which you previously dragged your color into. The color sample in the lower-left corner of the dialog box will match the color in the small square.

Close the dialog box by clicking the X button (Windows) or the red dot in the top corner of the dialog box (Mac). The color sample and checkerboard pattern will reflect the color you've set.

Click on the OK button to close the 'Document Setup' dialog box.

Click on the View (View Mode) in the menu bar.

Click on the Show Transparency Grid (Show Transparency Grid) option. This option is located at the bottom of the dropdown menu. Your background will change to the color you selected.
- Any objects filled or outlined with a color (including white) that differs from the background will be displayed.