[EXPERIMENTAL] New branch with "alt" aesthetic

A new branch experimental-custom-alt-style introduces a customisation option that thoroughly refashions the base background values of the themes, moving them away from their standard greyscale looks. This is experimental and subject to changes.

Here is the link: https://gitlab.com/protesilaos/modus-themes/-/commits/experimental-custom-alt-style

Note that I have taken extra care to respect the minimum 7:1 contrast ratio, so we are only considering an aesthetic tweak here. That granted, because the main background colour is no longer pure white/black, it is inevitably a bit closer to other background values. This means that the "alt" style may be slightly less usable, though that is something that should be assessed by the user (it is an option, after all).

And here is a demo:

Modus Operandi default vs alt

Screenshot_from_2020-08-22_10-09-48

Screenshot_from_2020-08-22_10-09-25

Modus Vivendi default vs alt

Screenshot_from_2020-08-22_10-09-50

Screenshot_from_2020-08-22_10-09-26

Edited by Protesilaos Stavrou