Comment 5 for bug 1427853

This fixes it. (the apps.css is provided by `elementary-theme` and is located at /usr/share/themes/elementary/gtk-3.0/)
Hope it'll get merged.

--- apps.css 2015-05-09 05:38:38.000000000 +0430
+++ apps.css 2015-05-16 10:54:53.199151000 +0430
@@ -116,14 +116,18 @@
                                   alpha (@bg_color, 0.98) 80%,
                                   alpha (shade(@bg_color, 0.94), 0.98)
                                   );
- box-shadow: inset 0 0 0 1px alpha (#fff, 0.10),
- inset 0 1px 0 0 alpha (#fff, 0.90),
- inset 0 -1px 0 0 alpha (#fff, 0.30),
+ box-shadow: inset 0 0 0 1px alpha (@base_color, 0.10),
+ inset 0 1px 0 0 alpha (@base_color, 0.90),
+ inset 0 -1px 0 0 alpha (@base_color, 0.30),
                 0 0 0 1px alpha (#000, 0.20),
                 0 3px 6px alpha (#000, 0.16),
                 0 3px 6px alpha (#000, 0.23);
 }

+.gala-notification .title, .gala-notification .label {
+ color: @text_color;
+}
+
 .gala-button {
     padding: 3px;
     color: #fff;