Use the Variations function to edit a photo's brightness and tinting "visually"—by viewing variations of the current picture and picking the best one.
To reach this function, use Effects | Variations in the Editor.
The preview at the far left shows the original picture. Use the three pictures directly to its right to lighten and darken it. Use the six pictures to the right of those to change its tinting. The column for lightening and darkening includes the original for comparison. The hexagon for tinting also includes the original for comparison. To edit the picture's colors, click the preview with the new look that you desire. To return to the picture's original look without leaving the window, click the preview of the original.
Use the slider at the top right to change the effect's Strength to any of five levels from Small to Large.