PDF Reader provides the text editing tool that enables you to replace the text size and color.
Change Text Size & Color:
1. Open the PDF and switch to the text editing mode.
2. Drag cursor over the text you want to modify to select it.
3. Right-click on the selected text, and choose "Font Size" or "Text Color" from the right-click menu to make changes to the text content.
4. Then click "Save" on the top of the page to save the changes.