I see the following leaks reported by valgrind:

==2727== 472 (52 direct, 420 indirect) bytes in 7 blocks are definitely lost in loss record 95 of 187
==2727==    at 0x4022525: malloc (vg_replace_malloc.c:149)
==2727==    by 0x47E24D5: g_malloc (gmem.c:131)
==2727==    by 0x47F6D2A: g_slice_alloc (gslice.c:824)
==2727==    by 0x47F7F61: g_slist_prepend (gslist.c:91)
==2727==    by 0x80586CA: listify_func (display.c:814)
==2727==    by 0x47CDAB5: g_hash_table_foreach (ghash.c:680)
==2727==    by 0x805A70E: meta_display_list_windows (display.c:836)
==2727==    by 0x805602D: meta_invalidate_default_icons (core.c:728)
==2727==    by 0x806E194: prefs_changed_callback (main.c:468)
==2727==    by 0x8073C7E: changed_idle_handler (prefs.c:250)
==2727==    by 0x47D8FA0: g_idle_dispatch (gmain.c:4132)
==2727==    by 0x47DAB6B: g_main_context_dispatch (gmain.c:2061)
==2727==    by 0x47DDF9E: g_main_context_iterate (gmain.c:2694)
==2727==    by 0x47DE348: g_main_loop_run (gmain.c:2898)
==2727==    by 0x806DDE5: main (main.c:392)
==2727==
==2727==
==2727== 720 bytes in 58 blocks are definitely lost in loss record 131 of 187
==2727==    at 0x4021864: calloc (vg_replace_malloc.c:279)
==2727==    by 0x47E243D: g_malloc0 (gmem.c:150)
==2727==    by 0x8080C5B: meta_color_spec_new (theme.c:986)
==2727==    by 0x808345B: meta_color_spec_new_from_string (theme.c:1096)
==2727==    by 0x80839A9: meta_color_spec_new_from_string (theme.c:1149)
==2727==    by 0x808987D: parse_color (theme-parser.c:725)
==2727==    by 0x808C0D0: start_element_handler (theme-parser.c:1907)
==2727==    by 0x47E0DC0: g_markup_parse_context_parse (gmarkup.c:1328)
==2727==    by 0x8090CE2: meta_theme_load (theme-parser.c:4595)
==2727==    by 0x8085E6A: meta_theme_set_current (theme.c:4489)
==2727==    by 0x8091937: meta_ui_set_current_theme (ui.c:718)
==2727==    by 0x806E194: prefs_changed_callback (main.c:468)
==2727==    by 0x8073C7E: changed_idle_handler (prefs.c:250)
==2727==    by 0x47D8FA0: g_idle_dispatch (gmain.c:4132)
==2727==    by 0x47DAB6B: g_main_context_dispatch (gmain.c:2061)
==2727==    by 0x47DDF9E: g_main_context_iterate (gmain.c:2694)
==2727==    by 0x47DE348: g_main_loop_run (gmain.c:2898)
==2727==    by 0x806DDE5: main (main.c:392)