Even though it's always best to configure color management when you first start a new project or scene, you may find it necessary to apply color management to existing scenes that do not use it yet. 
	 
- Open an existing scene that does not use color management. 
		
 
- Enable and configure color management as described in 
		  Configure color management. 
		
 
- If you do not see color management controls in panel toolbars, make sure that 
		  Renderer is set to 
		  Viewport 2.0. 
		
 
- If the 
		  Color Space attributes of the image inputs are not correct, you can change them manually as described in 
		  Specify the color space for textures and other image inputs. This applies to 
		  File textures and image planes. 
		  
If there are many nodes to change, it is probably quicker to define and reapply the color space input rules. See 
			 Change existing input color spaces automatically by reapplying rules. 
		  
 
		 
- Any colors and color ramps used by materials and lights in the scene are interpreted as being in the rendering color space. You may need to modify them as described in 
		  Inspect or pick color-managed color values.