How to change the text and background colour of a PDF

▶ 1. What you need

Only your browser. 123 PDF Editor PRO is a Chrome extension: it needs no desktop software, asks for no registration and works the same way on Windows, Mac and Linux.

1. Install the extension from the download page and click its icon in the toolbar.
2. Click Choose a PDF (or Open PDF) and select the document from your computer.
3. The file opens in the browser tab: from here you can work on text, images and pages.

✍️ 2. Changing the colour of the text

The colour is changed on the text already in the PDF, without retyping it. The editor recognises the original font, size and colour, so the result stays consistent with the rest of the page.

1. In the top bar choose the selection mode: Word to work on single words, Text block for a whole paragraph.
2. Click the text you want to change. The side panel shows the font, size and colour detected automatically.
3. Open the colour picker and choose the new shade: the change applies to your selection.
4. If you like, change the font as well (13 are included), plus size and style — bold, italic, underline, strikethrough and alignment.
5. Leave Auto-expand box to fit text switched on so the box adapts to the content if the new text is longer.

◩ 3. Changing the background colour or image

The background is applied behind the page content and can be a solid colour or an image taken from your computer. You can apply it to the whole document or to selected pages only.

1. Open the Background tool from the page tools bar.
2. Choose whether to use a solid colour or load a local image as the background.
3. Adjust the opacity if you want the background to stay discreet and not disturb reading.
4. Set the range of pages to apply it to: all of them, or only the ones you need.
5. Confirm to see the result straight away in the document preview.

▧ 4. Highlighting instead of colouring

If your aim is to make a passage stand out without altering the original text, highlighting is the cleaner route: it sits as a layer above the content and can be removed.

1. Use Highlighter to highlight a word or a line in the colour you prefer.
2. Alternatively open Annotations and comments to add sticky notes, rectangles, circles and comments that stay editable in compatible PDF readers.

⤓ 5. Saving and downloading the PDF

When you are happy with the result, you export the edited document to your computer. You can also set the work aside and pick it up later.

1. Click Download PDF to save the document with its new colour settings.
2. If you are not finished, use Save project and come back to it later from Projects.
3. Need to make the file lighter as well? Carry on with the guide on how to compress a PDF.

? 6. Frequently asked questions

The questions that come up most often on this topic.