Is there a way in Notepad++ to highlight a snippet of text and change it's background color? I would like it to remain that color within the editor for highlighting purposes. I don't want the color to change the code at all.
You can get the effect you want by right-clicking on the highlighted snippet and selecting "Style token" -> "Using (n)th style".
This will also highlight any other sections of your code which are identical to the one you selected, which may or may not be what you want. However the highlighting will only remain for as long as you have that file open in notepad++. If you close it, you will lose the highlighting.
In Notepad++
First select the line/words to be highlighted
Go to 'Search' Menu
Select 'Mark All'. There you will find 5 sub-menu as 'using [1..5]th style'.
(using 1st style : cyan colour) . (2nd : light brown) . (3rd : yellow) . (4th : purple) . (5th : green) .
However the highlighting will only remain for as long as you have that file open in notepad++. If you close it, you will lose the highlighting.
You can also define a language that set the snippet as a keyword and choose style for it.
来源：https://stackoverflow.com/questions/16176908/background-color-notepad-for-highlighting-purposes