fix(cc-dark-theme): minor improvements

- Fix dialog close button color.
- Fix color for error messages when loading threads.
- Fix "duplicate thread" dialog buttons color.

Fixed: twpowertools:193
Change-Id: Ie4048a0faf297b7cad9a75030bf9c63a42914b6d
diff --git a/src/ccDarkTheme/components/inputs/_pickers.scss b/src/ccDarkTheme/components/inputs/_pickers.scss
index 2cf091c..d551158 100644
--- a/src/ccDarkTheme/components/inputs/_pickers.scss
+++ b/src/ccDarkTheme/components/inputs/_pickers.scss
@@ -5,6 +5,14 @@
   border-color: var(--TWPT-subtle-border)!important;
 }
 
-.material-popup-content .popup-content .title {
-  color: var(--TWPT-primary-text)!important;
+.material-popup-content .popup-content {
+  header {
+    .title {
+      color: var(--TWPT-primary-text)!important;
+    }
+
+    material-button material-icon {
+      color: var(--TWPT-subtle-button-background)!important;
+    }
+  }
 }
diff --git a/src/ccDarkTheme/components/inputs/_selector.scss b/src/ccDarkTheme/components/inputs/_selector.scss
index e0a62f0..96650ac 100644
--- a/src/ccDarkTheme/components/inputs/_selector.scss
+++ b/src/ccDarkTheme/components/inputs/_selector.scss
@@ -34,7 +34,7 @@
     menu-item-groups .menu-item-label,
     menu-item-groups .label,
     menu-item-groups .text-segment {
-  color: rgba(255, 255, 255, .87)!important;
+  color: var(--TWPT-icon-color)!important;
 }
 
 .popup .item-group-list material-icon {