Aperture: Avoid hardcoded hex colors where possible

Change-Id: I58cfdec3782bf1706029494850ee73ae65eedc1f
diff --git a/app/src/main/res/color/lens_selector_button_background.xml b/app/src/main/res/color/lens_selector_button_background.xml
index 8fe4c38..70c0ddb 100644
--- a/app/src/main/res/color/lens_selector_button_background.xml
+++ b/app/src/main/res/color/lens_selector_button_background.xml
@@ -5,5 +5,5 @@
 -->
 <selector xmlns:android="http://schemas.android.com/apk/res/android">
     <item android:color="@color/black" android:state_enabled="true" />
-    <item android:color="#2A3232" android:state_enabled="false" />
+    <item android:color="@color/gray_60" android:state_enabled="false" />
 </selector>
diff --git a/app/src/main/res/drawable/ic_drag_handle.xml b/app/src/main/res/drawable/ic_drag_handle.xml
index 97205b8..50c5bf7 100644
--- a/app/src/main/res/drawable/ic_drag_handle.xml
+++ b/app/src/main/res/drawable/ic_drag_handle.xml
@@ -5,6 +5,6 @@
 -->
 <shape xmlns:android="http://schemas.android.com/apk/res/android"
     android:shape="rectangle">
-    <solid android:color="#FFFFFFFF" />
+    <solid android:color="@color/white" />
     <corners android:radius="2dp" />
 </shape>
diff --git a/app/src/main/res/drawable/primary_bar_layout_background.xml b/app/src/main/res/drawable/primary_bar_layout_background.xml
index 67dbeaf..3c2df94 100644
--- a/app/src/main/res/drawable/primary_bar_layout_background.xml
+++ b/app/src/main/res/drawable/primary_bar_layout_background.xml
@@ -6,7 +6,7 @@
 <layer-list xmlns:android="http://schemas.android.com/apk/res/android">
     <item>
         <shape android:shape="rectangle">
-            <solid android:color="#2A3232" />
+            <solid android:color="@color/gray_60" />
         </shape>
     </item>
     <item android:top="4px">
diff --git a/app/src/main/res/values/themes.xml b/app/src/main/res/values/themes.xml
index 405a56c..fbe057e 100644
--- a/app/src/main/res/values/themes.xml
+++ b/app/src/main/res/values/themes.xml
@@ -16,7 +16,7 @@
         <item name="colorOnSecondary">@color/black</item>
         <!-- Secondary container -->
         <item name="colorOnSecondaryContainer">@color/white</item>
-        <item name="colorSecondaryContainer">#2a3232</item>
+        <item name="colorSecondaryContainer">@color/gray_60</item>
         <!-- Status bar color. -->
         <item name="android:statusBarColor">?attr/colorOnPrimary</item>
         <!-- Customize your theme here. -->