The Highlight Text tool in Adobe Acrobat is one of the commenting tools and is "the markup tool of choice to highlight and comment on type (rather than suggesting edits)," according to Taz Tally in "Layers Magazine." Once you highlight a portion of text with this tool, double-clicking on the text will bring up a comment window where you enter comments. When the cursor moves over the highlighted area, or the highlighted area is clicked, the comments appear. The default highlight text tool color is yellow, but it can be changed.
Go to the "View" menu in Adobe Acrobat and highlight "Toolbars." Select "Comment & Markup." The "Comment & Markup" toolbar will appear at the top of the document.
Click on the "Highlight Text" icon. It appears as the letter "T" with yellow highlighting.
Click on a portion of text with the tool and drag the tool to highlight the text.
Right-click or Control-click on the text to bring up the contextual menu. Select "Properties."
Click on the "Appearance" tab. Click on the block of color. Select a color from the options or click "Other Color" to use the color selection wheel. Adjust the "Opacity" setting, if desired.
Check the option to "Make Properties Default" if you would like to use this color every time you use the Highlight Text tool. Click "OK" to leave the "Highlight Properties" window.