Yes, you can set your background to a preset or a fully custom color from the Settings menu.

Using a Copic Color

1. Open the Settings menu.
2. Go to the Workspace section and tap Background.
3. Select Custom Color.
4. Choose a color from the Copic color wheel to set it as your background.

Using a Custom Color from an Image

1. Use the Color Picker to sample a color from an imported photo or screenshot.
2. Draw a small stroke on the canvas with your new custom color.
3. Select the stroke and tap the paperclip icon in the selection popup. This copies the stroke's color to your clipboard.
4. You can now delete the temporary stroke from your canvas.
5. Return to Settings > Workspace > Background and select Custom Color.
6. Your new color will appear in the inner ring of the color wheel. Tap it to set it as your background.