I am extremely annoyed to realize that it is IMPOSSIBLE to find the basic colors of the #Gnome interface in #GTK v4.

@metal3d the default GTK4 theme does not provide any source of stability for the colors, mostly because it never did, not even in GTK2 or GTK3; libadwaita, on the other hand, does: https://gnome.pages.gitlab.gnome.org/libadwaita/doc/1-latest/named-colors.html

@metal3d but if you want to *draw* with CSS colors, then you need to use the gtk_render_* API in GTK3, and the GtkSnapshot API in GTK4. That has been the case since GTK 3.0. The old "ask the style machinery for a color" made sense in GTK2, where you only had colors. With the introduction of CSS, you can have gradients, textures, blended layers, or (most likely) a transparent value. There is no "color" to be queried in many cases.

@metal3d It's not a case of being "better" or "worse" (though CSS allows us to do better rendering without loading shared modules that literally put pixels inside widgets, like GTK2 engines did); it's a case of being an entirely different API.

@ebassi that's not to draw on GTK. That's to get the theme generic colors (background and foreground) to color an app using another library (fyne.io).
There is no dark/light information on gnome and nothing to get the theme base colors.
Actually I call some gjs command to get a invisible one shot window color from get_context() method. Grk4 abandoned this.

@ebassi that's something that I don't understand... OK, css is cool to make whatever we want for themes. But there are at least 2 needed information, the "dakmrk/light" switch and "foreground/background" colors. That's anormal to have to call GJS (or python) from another language/lib to find this. And anormal that now it's impossible to get these information.

@ebassi sorry for my English and sorry if I'm a bit annoyed but I spent hours to read documentation about GTK 4 to finally realize that I will not be able to continue my idea...

@metal3d I understand the annoyance, but really: what you want to achieve was never supported in 20+ years, and it's not really supportable programmatically.

At most, you can emulate the appearances of libadwaita by looking at the generated CSS, and by using the documentation; for anything else, you'll have to use the good old Eyeball Mk 1, or the GTK inspector, and then emulate the result.

@ebassi the goal is to be able, from fyne app (in go) to get information about the current gnome theme colors. Not to get the Css file or attributes with inspector to create the theme by hand.