The Levels tool has two-channel modes (combined RGB and individual Red, Green, and Blue) between which you can switch manually by using the tabs. However, to apply auto levels correction or use the shadow and highlight pickers for each, you must select the appropriate mode from the application preferences.
- Select an image from the Browser.
- Go to the Exposure Inspector and navigate to the Levels tool.
- From the Level’s tool title bar, click on the Action button (… icon) and select Preferences…
- Alternatively, select Capture One/Edit (macOS/Windows) -> Preferences from the main menu. The Preferences dialog window opens.
- From the Levels tool area, select the appropriate Channel Mode from the fly-out menu.