This just extends Roundcube's Elastic skin with some dark theme colours.

It's part of the Roundcube now, so it should be there, but just in case. This only extends the Elastic skin, by adding some additional css, but requires the base to be installed.

In your roundcube/skins folder run this:

git clone https://github.com/tborychowski/elastic-dark.git

alternatively, if you don't have git installed, you can just get the zip instead:

wget wget -O elastic-dark.zip https://github.com/tborychowski/elastic-dark/archive/master.zip
unzip elastic-dark.zip
mv elastic-dark-master elastic-dark

Please note: you may need to use sudo for some commands, depending on your setup.

RoundCube v1.5-beta introduced some small template changes, so to get the compatible skin version, please check-out the v1.5-beta branch of this repo (run this after git clone...):

git checkout v1.5-beta

Change the skin in Roundcube's Settings/User Interface to Elastic Dark.

For login screen to work, you also need to update the roundcube/config/config.inc.php with:

$config['skin'] = 'elastic-dark';

Unfortunately that seems to require a manual edit to one of the RC core php files (or a js plugin that would fix that). For the former solution open roundcube/program/steps/mail/func.inc and in rcmail_html4inline function add an entry to the $replace array: '/!important/' => '', (around line 1113), so that it looks like this:

    $replace = array(
        // add comments around html and other tags
        '/(<!DOCTYPE[^>]*>)/i'          => '<!--\\1-->',
        '/(<\?xml[^>]*>)/i'             => '<!--\\1-->',
        '/(<\/?html[^>]*>)/i'           => '<!--\\1-->',
        '/(<\/?head[^>]*>)/i'           => '<!--\\1-->',
        '/(<title[^>]*>.*<\/title>)/Ui' => '<!--\\1-->',
        '/(<\/?meta[^>]*>)/i'           => '<!--\\1-->',
        // quote <? of php and xml files that are specified as text/html
        '/<\?/' => '&lt;?',
        '/\?>/' => '?&gt;',
        '/!important/' => '',
    );

Unfortunately, this needs to be re-applied after every update of the Roundcube.

The whole css has been "borrowed" from Skorpion/roundcube-elastic-dark (with some small tweaks).