Theme: use other exported colors

Adwaita and Yaru both export colors at the top of their CSS file from within this source files:
https://gitlab.gnome.org/GNOME/gtk/blob/master/gtk/theme/Adwaita/_colors-public.scss#L84
https://gitlab.gnome.org/GNOME/gtk/blob/gtk-3-24/gtk/theme/Adwaita/_colors-public.scss

gnome-software uses some of those colors in their in-app CSS that overwrites the global gtk theme:
https://gitlab.gnome.org/GNOME/gnome-software/blob/master/src/gtk-style.css

Most likely those are the correct colors. In three cases sadly not and it is too late to get an upstream change for 20.04 now because gnome is already in UI freeze for this cycle:

1) The round checkmarks inside the App boxes that show that the app is installed are orange instead of green, which is semantically wrong since they are not selected and should instead show that you successfully installed that app:

https://gitlab.gnome.org/GNOME/gnome-software/blob/master/src/gtk-style.css#L12
Change
.installed-icon {
 color: @theme_selected_bg_color;
}
to
.installed-icon {
 color: @success_color;
}
https://gitlab.gnome.org/GNOME/gtk/blob/gtk-3-24/gtk/theme/Adwaita/_colors-public.scss#L84
-> exported to: https://gitlab.gnome.org/GNOME/gtk/blob/gtk-3-24/gtk/theme/Adwaita/gtk-contained.css#L2021

2) The little [1] boxes inside the "stackswitcher" in the headerbar (it's actually a buttonbox in this case, but this is offtopic) that show up if you are either installing X apps or have X updates would be orange, if we would not "hack" a biiiig box-shadow over them to make them green. This is first of all a dirty hack and secondly there are little orange pixels showing up at the rounding
Change
.counter-label {
 ...
 ...
 background-color: mix(@theme_selected_bg_color, @theme_selected_fg_color, 0.3);
 ...
 ...
 ...
}

To
.counter-label {
 ...
 ...
 background-color: @success_color;
 ...
 ...
 ...
}
https://gitlab.gnome.org/GNOME/gnome-software/blob/master/src/gtk-style.css#L422

3) The "given" stars are not visible in both Adwaita and Yaru dark. For some reason, upstream transparentizes them into oblivion with the "shade-function". The enabled stars should just use the theme's fg color:
Change
.star-enabled,
.star-enabled:disabled {
 color: shade(@theme_fg_color, 0.8);
}
to
.star-enabled,
.star-enabled:disabled {
 color: @theme_fg_color;
}
https://gitlab.gnome.org/GNOME/gnome-software/blob/master/src/gtk-style.css#L412

Thank you very much in advance! I try to get this into gnome-shell's upstream repo in the next cycle