Tested on Roundcube 1.3.x and 1.2.x. Is known to work with 1.1.4 Mabola can change and will not be tested in this version.
Mabola is a clean and usable skin for latest Roundcube Webmail (http://roundcube.net). Is based on Material Design, Bootstrap and inherits from Larry Skin, so there should be no unstyled content.
It supports Threecol plugin. Check it out at EstudioNexos/threecol.
Icons are from https://github.com/laclasse-com/roundcube_laclasse_skin.
Screenshots at http://www.estudionexos.com/mabola-skin-for-roundcube.html
Only available color variation at the moment is Blue (although we have other colors in production)
https://github.com/EstudioNexos/mabola-blue
Just put zip file from https://github.com/EstudioNexos/mabola/archive/master.zip in your roundcube/skins folder.
Then uncompress zip file and rename "mabola-master" to "mabola" (zip file can be deleted if it is still around)
After that you can go to your roundcube user preferences and choose Mabola.
Mabola skin is know included in "Mail-In-A-Box"* great mailing server setup package. https://discourse.mailinabox.email/t/install-mabola-skin-for-roundcube-mail/1520/11
User Claudio Ferreira Filho filhocf has created a docker file which includes Roundcube, Mabola Skin and other interesting Roundcube plugins:
https://hub.docker.com/r/filhocf/roundcube/
LICENSE for Mabola Skin: GNU General Public License v3 See http://www.gnu.org/licenses/gpl-3.0.en.html for details
LICENSE for Laclasse Icons:
The contents of this folder are subject to the Creative Commons Attribution-ShareAlike License. It is allowed to copy, distribute, transmit and to adapt the work by keeping credits to the original autors in the README file. See http://creativecommons.org/licenses/by-sa/3.0/ for details.