valgrind reports memory leak of 96 bytes in the following code line:
      vte_terminal_set_colors (VTE_TERMINAL (screen->terminal),
                               has_fg ? &fg : NULL,
                               has_bg ? &bg : NULL,
                               palette, 16);
The leak disappears if I pass 0 as palette_size (the last parameter).

The leak seems to come from here:
vtegtk.cc:2888
        vte::color::rgb* pal = nullptr;
        if (palette_size) {
                pal = g_new0(vte::color::rgb, palette_size);
                for (gsize i = 0; i < palette_size; ++i)
                        pal[i] = vte::color::rgb(palette[i]);
        }

        auto impl = IMPL(terminal);
        impl->set_colors(foreground ? &fg : nullptr,
                         background ? &bg : nullptr,
                         pal, palette_size);
        impl->set_background_alpha(background ? background->alpha : 1.0);
pal does not get freed.