micro/runtime/help/colors.md

Colors

This help page aims to cover two aspects of micro's syntax highlighting engine:

• How to create colorschemes and use them
• How to create syntax files to add to the list of languages micro can highlight

Colorschemes

Micro comes with a number of colorschemes by default. Here is the list:

• simple: this is the simplest colorscheme. It uses 16 colors which are set by your terminal

• mc: A 16-color theme based on the look and feel of GNU Midnight Commander. This will look great used in conjunction with Midnight Commander.

• nano: A 16-color theme loosely based on GNU nano's syntax highlighting.

• monokai: this is the monokai colorscheme; you may recognize it as Sublime Text's default colorscheme. It requires true color to look perfect, but the 256 color approximation looks very good as well. It's also the default colorscheme.

• zenburn: The 'zenburn' colorscheme and works well with 256 color terminals

• solarized: this is the solarized colorscheme. You should have the solarized color palette in your terminal to use it.

• solarized-tc: this is the solarized colorscheme for true color; just make sure your terminal supports true color before using it and that the MICRO_TRUECOLOR environment variable is set to 1 before starting micro.

• atom-dark-tc: this colorscheme is based off of Atom's "dark" colorscheme. It requires true color to look good.

• cmc-16: A very nice 16-color theme. Written by contributor CaptainMcClellan (Collin Warren.) Licensed under the same license as the rest of the themes.

• cmc-paper: Basically cmc-16, but on a white background. ( Actually light grey on most ANSI (16-color) terminals.)

• cmc-tc: A true colour variant of the cmc theme. It requires true color to look its best. Use cmc-16 if your terminal doesn't support true color.

• codeblocks: A colorscheme based on the Code::Blocks IDE's default syntax highlighting.

• codeblocks-paper: Same as codeblocks, but on a white background. ( Actually light grey. )

• github-tc: A colorscheme based on Github's syntax highlighting. Requires true color to look its best.

• paper-tc: A nice minimalist theme with a light background, good for editing documents on. Requires true color to look its best. Not to be confused with -paper suffixed themes.

• geany: Colorscheme based on geany's default highlighting.

• geany-alt-tc: Based on an alternate theme bundled with geany.

• flamepoint-tc: A fire inspired, high intensity true color theme written by CaptainMcClellan. As with all the other -tc suffixed themes, it looks its best on a

To enable one of these colorschemes just press CtrlE in micro and type set colorscheme solarized. (or whichever one you choose). You can also use set colorscheme monochrome if you'd prefer to have just the terminal's default foreground and background colors. Note: This provides no syntax highlighting!

See help gimmickcolors for a list of some true colour themes that are more just for fun than for serious use. ( Though feel free if you want! )

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Creating a Colorscheme

Micro's colorschemes are also extremely simple to create. The default ones can be found here.

They are only about 18-30 lines in total.

Basically to create the colorscheme you need to link highlight groups with actual colors. This is done using the color-link command.

For example, to highlight all comments in green, you would use the command:

color-link comment "green"

Background colors can also be specified with a comma:

color-link comment "green,blue"

This will give the comments a blue background.

If you would like no foreground you can just use a comma with nothing in front:

color-link comment ",blue"

You can also put bold, or underline in front of the color:

color-link comment "bold red"

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There are three different ways to specify the color.

Color terminals usually have 16 colors that are preset by the user. This means that you cannot depend on those colors always being the same. You can use those colors with the names black, red, green, yellow, blue, magenta, cyan, white and the bright variants of each one (brightblack, brightred...).

Then you can use the terminals 256 colors by using their numbers 1-256 (numbers 1-16 will refer to the named colors).

If the user's terminal supports true color, then you can also specify colors exactly using their hex codes. If the terminal is not true color but micro is told to use a true color colorscheme it will attempt to map the colors to the available 256 colors.

Generally colorschemes which require true color terminals to look good are marked with a -tc suffix and colorschemes which supply a white background are marked with a -paper suffix.

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Here is a list of the colorscheme groups that you can use:

• default (color of the background and foreground for unhighlighted text)
• comment
• identifier
• constant
• statement
• symbol
• preproc
• type
• special
• underlined
• error
• todo
• statusline ( Color of the statusline)
• tabbar ( Color of the tabbar that lists open files.)
• indent-char ( Color of the character which indicates tabs if the option is enabled)
• line-number
• gutter-error
• gutter-warning
• cursor-line
• current-line-number
• color-column
• ignore
• divider ( Color of the divider between vertical splits. )

Colorschemes must be placed in the ~/.config/micro/colorschemes directory to be used.

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In addition to the main colorscheme groups, there are subgroups that you can specify by adding .subgroup to the group. If you're creating your own custom syntax files, you can make use of your own subgroups.

If micro can't match the subgroup, it'll default to the root group, so it's safe and recommended to use subgroups in your custom syntax files.

For example if constant.string is found in your colorscheme, micro will use that for highlighting strings. If it's not found, it will use constant instead. Micro tries to match the largest set of groups it can find in the colorscheme definitions, so if, for examle constant.bool.true is found then micro will use that. If constant.bool.true is not found but constant.bool is found micro will use constant.bool. If not, it uses constant.

Here's a list of subgroups used in micro's built-in syntax files.

• comment.bright ( Some filetypes have distinctions between types of comments.)
• constant.bool
• constant.bool.true
• constant.bool.false
• constant.number
• constant.specialChar
• constant.string
• constant.string.url
• identifier.class ( Also used for functions. )
• identifier.macro
• identifier.var
• preproc.shebang ( The #! at the beginning of a file that tells the os what script interpreter to use. )
• symbol.brackets ( {}()[] and sometimes <> )
• symbol.operator ( Color operator symbols differently. )
• symbol.tag ( For html tags, among other things.)
• type.keyword ( If you want a special highlight for keywords like private )

In the future, plugins may also be able to use color groups for styling.

Syntax files

The syntax files specify how to highlight certain languages.

Micro's builtin syntax highlighting tries very hard to be sane, sensible and provide ample coverage of the meaningful elements of a language. Micro has syntax files built int for over 100 languages now. However, there may be situations where you find Micro's highlighting to be insufficient or not to your liking. Good news is you can create syntax files (.micro extension), place them in ~/.config/micro/syntax and Micro will use those instead.

The first statement in a syntax file will probably the syntax statement. This tells micro what language the syntax file is for and how to detect a file in that language.

Essentially, it's just

syntax "Name of language" "\.extension$"

For the extension, micro will just compare that regex to the filename and if it matches then it will use the syntax rules defined in the remainder of the file.

There is also a possibility to use a header statement which is a regex that micro will compare with the first line of the file. This is almost only used for shebangs at the top of shell scripts which don't have any extension (see sh.micro for an example).

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The rest of a syntax file is very simple and is essentially a list of regexes specifying how to highlight different expressions.

It is recommended that when creating a syntax file you use the colorscheme groups (see above) to highlight different expressions. You may also hard code colors, but that may not look good depending on what terminal colorscheme the user has installed.

Here is an example to highlight comments (expressions starting with //):

color comment "//.*"

This will highlight the regex //.* in the color that the user's colorscheme has linked to the comment group.

Note that this regex only matches the current line. Here is an example for multiline comments (/* comment */):

color comment start="/\*" end="\*/"

Note: The format of syntax files will be changing with the view refactor. If this help file still retains this note but the syntax files are yaml please open an issue.