To change the color used for the highlight, choose Tools > Show Colors.
To add highlight buttons to the toolbar, choose View > Customize Toolbar and drag the buttons to the toolbar. You can also use toolbar buttons to add highlights.
Select the text you want to highlight or region you want to circle. Choose Tools > Note Type > Circle, Tools > Note Type > Box, Tools > Note Type > Highlight, Tools > Note Type > Underline, or Tools > Note Type > Strike Out. You may drag circle and box highlights in the document until the highlight is located where you want and has the size you want. Choose Notes > Circle, Notes > Box, Notes > Highlight, Notes > Underline, or Notes > Strike Out. To highlight a section of a PDF document: