[CRD iOS] Fix color scheme and other UI issues

remoting/ios/app/remoting_theme.h

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef REMOTING_IOS_APP_REMOTING_THEME_H_
+#define REMOTING_IOS_APP_REMOTING_THEME_H_
+
+#import <UIKit/UIKit.h>
+
+// Styles to be used when rendering the iOS client's UI.
+@interface RemotingTheme : NSObject
+
+@property(class, nonatomic, readonly) UIColor* hostListBackgroundColor;
+@property(class, nonatomic, readonly) UIColor* connectionViewBackgroundColor;
+@property(class, nonatomic, readonly) UIColor* onlineHostColor;
+@property(class, nonatomic, readonly) UIColor* offlineHostColor;
+
+@end
+
+#endif  // REMOTING_IOS_APP_REMOTING_THEME_H_