[Geary] Dark background

[Pétùr <peturvilj gmail com>]

Hi,

Geary is to bright for me. 

I would like to change the background color of the message writing panel for something darker.

Some themes change the background of the folder list panel and the messages list panel. But the more important for me is to change the message writing panel (because it is where my eyes spend the most time).

I am aware this is probably because email are written in html in Geary and this set the white color for background. But I deactivate the option "compose as html" in dconf-editor ; with no effect (I still have the makeup buttons ; it seems this option triggers nothing).

What is the proper way to change background for message writing?

P-S : I am using Xfce with the arc-darker theme. I would prefer a solution which does not involves themes changing (and apply only to geary ).