@Hans-van-Gelderen ,
I am using the “Bespin” theme.
The theme, which is just a color/style mapping of identified keywords in a certain context, should be irrelevant.
If the theme were set up correctly, then it would be irrelevant. But maybe the theme is out of date.
Think of the theme as a mapping from the named settings in Notepad++ to the numbered array in the lexer (which is part of another separately-maintained codebase, known as Scintilla).
Assume, for example, that in the “old days”, the CSS lexer expected “SETTING A” to be mapped to ID=1 and “SETTING B” to be mapped to ID=2. Then assume the “Bespin” theme was created. Then assume Scintilla changed the CSS mapping to expect “SETTING A” to be mapped to ID=3 and “SETTING B” to be mapped to ID=4. The default theme in Notepad++ was then updated, but no one updated the “Bespin” theme. So you tell the Bespin theme “I want these colors for SETTING A and SETTING B”, and the theme maps those to ID 1 and 2, and the lexer doesn’t see them because it’s looking for 3 and 4. Hence, the theme is not irrelevant to the conversation. (Note, I am not saying this is for-certain the case for the Bespin theme and CSS lexer; I am just saying it’s not out of the realm of possibility; I use the default theme, and rarely edit standalone CSS.)
Thus, because it might very well be the theme, for debugging purposes, please try the default theme.
If you are in the position to get Notepad++ enhanced in this respect
This is a forum for the Community of Notepad++ users. Some here have contributed to the codebase, but the primary developer uses the forum mostly for announcements. And this is especially not a 1-on-1 support desk, where you can expect that I am now committed to solve your problem for you – I voluntarily read and answer in this forum, to help other Notepad++ make good use of the tool, but I am not part of the “in crowd” or a paid employee, and you cannot assume that I will always be available.
Feature requests and bug reports do not go in the Forum – but really, the forum is a good first-line of support, to help educate users before feature requests are made: maybe there is already a way to accomplish the goal in an alternate manner.
I noticed also other keywords in HTML, CSS and Javascript colored/styled wrongly
If it’s colored or styled wrongly in the default styler, then show us where you think it’s wrong, and there’s probably a bug (or a misunderstanding of what the correct behavior is); otherwise, the theme is likely to blame. As I’ve said, the developers don’t regularly update the themes that are bundled with Notepad++.