Hello, everyone.
This is an update to the dark theme I made a while ago.
In this version, thanks to tips from @rudantu, who is proposing a redesign of the website and app, I have made some adjustments to the theme, specifically to the search boxes, sliders, different icon states, and other details.
Search boxes detail at the top bar.
Different emphases on lighttable images: rejected, not selected, selected, hover, colors and groups.
Different colors for the on/off icons states in the modules and shadow in the search box.
Different grayscale range in the tone curve.
Transparent sliders in the color equalizer graph. alpha(0.2)
Back to black in the scopes 
and some shadows in info popup windows.
(UPDATED) borders of the app with the same background color.
/* Sets outer borders that could be hide or shown in darktable with 'b' shortcut */
#outer-border
{
background-color: @grey_15;
min-width: 1.4em;
}
Some changes to the splash screen.
As before, unzip the user.zip file, use the “darktable icons darker” theme as a basis, copy and paste the contents of user.css into the darktable configuration window, apply the changes, and restart darktable.
Here is the theme:
user.zip (7.4 KB)
Once again, infinite thanks to the developers of darktable who make it possible for this program to get better every day with the new updates they release.
Greetings from Mérida, Yucatán.