lxdm adapted theme
Here come my /etc/lxdm/*.conf and the adapted theme: I took industrial which comes by default and changed it by some conf i found in the arch and majaro theme. Moreover i adapted all to be in line with the style guides for Devuan. Please be so kind and try out, if it works for you "out of the box", i.e. throwing in the tweaked Industrial theme and changing the corrisponding lines in /etc/lxdm/lxdm.conf (there i also a tool called lxdm-config, which allows to choose an avatar when called as user and to configure some more stuff when called as root).
Nice weekend though :)
PS. I forgot: Eventually you have to rename, in /usr/share/lxdm/Industrial/ the file wave.svg to background-image.png (?)
Meanwhile i got working a clean ascii installation on qemu, using lxde in tasksel.
Throwing in the lxdm configs above, i see there are still lots of errors. I'll correct them and i'll try to get styling closer to the purpy defaults.
Generally, as for devuan artworks: it's a bit a chaos. There are no style guidelines. The font infos i got from hellekin (Open Sans  and Source Code Pro for mono obviously are intent only for web. As for the fonts "inline" the desktop i got the info: go with the system defaults. But in debian (differently from ubuntu) there are no default fonts, as far as i know. There are coming several (ttf) fonts with any basic installation (like sans, serif, Liberation). Boh ...
The Clearlooks-Phenix theme (adapted to gtk3 too, in theory) does not work well with, several, gtk3 apps .
For the moment i will procede like this:
i'll try to stay as close as possible to what i see for devuan artworks (some colours etc.), for the fonts may be sans and mono
i'll try to tweak a standard debian theme (possibly one which is similar to Clearlooks-Phenix but better with gtk3; Crux may be or Industrial) to dark and flat
i'll use the nooblabs ultra-flat-icons (blue) (and not the standard gnome greyish ones).
When that is done, i'll make an as small as possible (qemu) disk which you when you have the time can try to start and see if it works for you as well. From that step on, we could think of a way how to make it a testing live-iso which we could give to others as well.
If i'm allowed to assign something to you: Please be so kind and check, if and how the debian menu (re)generation mechanism can be tweaked to be more userfriendly and in line with the standard freedesktop structure. Me, for the moment, i'll continue to use xdgmenumaker - simply to play around the basic problem.Edited by E. Ninger