Change theme colors

Marketing requested change to the colors of the expand icon and the
section headers in the sidebar.

Testing: Viewed rendered output in browser. No changes made to links or
content.

This commit has no associated issue, quick fix.

Signed-off-by: Katrina Prosise <[email protected]>

source/_static/theme_overrides.css

@@ -104,4 +104,11 @@ html.writer-html5 .rst-content dl.field-list>dt:after {
 }
 .wy-nav-side {
       background: #2C1256;
-    }
+}
+
+.wy-menu-vertical li button.toctree-expand{
+  color: #ffffff;
+}
+.wy-menu-vertical header, .wy-menu-vertical p.caption {
+  color: #e4960b;
+}