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 tool tab and navigate to the Levels tool.
- From the Level’s tool title bar, click on the Action menu, the (…) icon, and select Preferences…
- Alternatively, select Capture One/Edit (macOS/Windows) -> Preferences from the main menu. The Preferences dialog window opens.
- Go to the Exposure tab. From the Levels Tool area, select the appropriate Channel Mode from the fly-out menu.