Description of problem:
When using the Clearlooks-Phénix theme with Gtk3 applications, I get a lot of Gtk warning messages .

Version-Release number of selected component (if applicable):
7.0.1-3.el7 

How reproducible:
Every time

Steps to Reproduce:
1. Select the Clearlooks-Phénix theme... I'm using MATE right now, so I'll use System->Preferences->Look and Feel->Appearance
2. Open a terminal window.
3. In the terminal, type "gnote" and hit Enter.

Actual results:
The application starts and there doesn't appear to be anything particularly wrong with the way it looks, but the following messages appear in the terminal

(gnote:11355): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:161:27: The style property GtkButton:image-spacing is deprecated and shouldn't be used anymore. It will be removed in a future version

(gnote:11355): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:162:26: The style property GtkButton:inner-border is deprecated and shouldn't be used anymore. It will be removed in a future version

(gnote:11355): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:586:27: The style property GtkButton:image-spacing is deprecated and shouldn't be used anymore. It will be removed in a future version

(gnote:11355): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:587:28: The style property GtkWidget:interior-focus is deprecated and shouldn't be used anymore. It will be removed in a future version

(gnote:11355): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:588:28: The style property GtkButton:default-border is deprecated and shouldn't be used anymore. It will be removed in a future version

(gnote:11355): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:589:26: The style property GtkButton:inner-border is deprecated and shouldn't be used anymore. It will be removed in a future version

(gnote:11355): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:1341:25: The style property GtkRange:slider-width is deprecated and shouldn't be used anymore. It will be removed in a future version

(gnote:11355): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:1342:25: The style property GtkRange:stepper-size is deprecated and shouldn't be used anymore. It will be removed in a future version

(gnote:11355): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:1343:34: The style property GtkScrollbar:min-slider-length is deprecated and shouldn't be used anymore. It will be removed in a future version

(gnote:11355): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:1344:28: The style property GtkRange:stepper-spacing is deprecated and shouldn't be used anymore. It will be removed in a future version

(gnote:11355): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:1345:34: The style property GtkRange:trough-under-steppers is deprecated and shouldn't be used anymore. It will be removed in a future version

(gnote:11355): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:1602:13: not a number

(gnote:11355): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:1602:13: Expected a string.

(gnote:11355): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:1984:11: not a number

(gnote:11355): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:1984:11: Expected a string.

(gnote:11355): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:2534:11: not a number

(gnote:11355): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:2534:11: Expected a string.

(gnote:11355): Gtk-WARNING **: Theme parsing error: applications.css:21:0: Expected a valid selector


Expected results:
The application starts without any warnings.

Additional info:
I get similar results for other applications, too.