Implement highlighted placeholder in text

[Thoufak]

I would like to insert a placeholder in the text. The user is then supposed to replace the palceholder's text with the real value. Is there a way to highlight this placeholder to make it visually distinct from the rest of the text, e.g. change its background color?

Please find a screenshot below that illustrates my idea. There, placeholders have a cyan background. And as the user deletes them and inputs the values instead of them, the background should become normal (white).

How do I implement this or something similar?