You can adjust the relative lightness of a picture (brightness) or the difference between the darkest and lightest areas (contrast) by using the options below.
When you change options in this dialog box, the changes are immediately applied to your shape, making it easy to see the effects of the changes in your SmartArt graphic, or shape without closing the dialog box. However, since the changes are instantly applied, it is not possible to click Cancel in this dialog box. To remove changes, you must click Undo on the Quick Access Toolbar for each change that you want to remove.
You can simultaneously undo multiple changes that you made to one dialog box option, as long as you did not make changes to another dialog box option in between.
You may want to move the dialog box so that you can see both the shape or slide background and the dialog box at the same time.
Tip: To change the shape of your picture, or to add effects such as shadows, reflections, and glows, under Picture, on the Format tab, in the Picture Styles group, click Picture Shapes or Picture Effects.
Recolor To give the object or slide background a stylized effect, such as grayscale or sepia tone, click this button, and then click the option that you want.
Brightness Move the Brightness slider, or enter a number in the box next to the slider.
Contrast Move the Contrast slider, or enter a number in the box next to the slider.
Reset picture Restores the picture to the default settings for Brightness and Contrast.