How to change colouring scheme for a file extension?

There is not yet a graphical UI to handle this but it can be done nonetheless by editing the syntaxcolouring.xml file.

You can load the file in ECMerge and edit it (use XML pretty-printing feature to get it in a better shape).

Each /syntax-colouring/lexer/association node contains an extensions attribute, you can add or change these extensions. For example, if you would prefer Hypertext colouring scheme for .ASP file, you can do that:

• search *.asp (the default scheme is asp), remove the extension from the list
• search language="Hypertext"  and add *.asp to the list of extensions

If you want another colour or change bold/normal font for a style, you can have a look to the style nodes under a scheme (lexer nodes). The notation is the HTML notation (i.e. a font tag, with color and bgcolor attributes, use "bold=yes" for bold, italic="yes" for italic). Note that background colours are ignored in differentiation mode, so as not to interfer with differences background colours.