How do I set the colour of a custom tag in html-mode

Question

Trying to get a mode to work with silverstipe templates.

How do I set the background of the <% %> tag to be a darker color?

Answer 1

You can customize any face using the customization system, but the trick is to know which face you have to edit to get the look that you want. There is a shortcut you can use in this case: position the point over the text in question and run M-x describe-face. This asks for a face name, but the default if you leave the input blank is the face used by the text at point. This gets you a help window with information about the face, including a link that takes you to its customization page.

Answer 2

According to your link, the face that highlights <% and %> is face font-lock-keyword-face.

If you want that face to be darker everywhere, then customize it, as @db48x suggested.

If you instead want to leave that face alone but have <% and %> be darker in silverstripe-mode then use a different, darker face in your font-lock-add-keywords expression. Use defface to define a new face, and use that.