When Callout shapes are used wisely, they can be impactors that convey a message. The attribution and positioning of the callouts has to be proper so that your audiences do not get lost. When inserted, Callouts take default formatting attributes from the Theme applied to the presentation, just like any other PowerPoint shape. You can later change their fill and/or outline and also apply a shape effect to them in the same way as you would do for any PowerPoint shape.
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