This is something I just ran into recently. When trying to push Internet Settings via GPO, some settings do not seem to be pushed even though other settings are. For example, when trying to push proxy server settings, the checkbox to enable specifying a proxy server gets pushed to clients, but the proxy server address entered in the box does not. So the client ends up with the proxy option enabled, but a blank (or unchanged) server textbox.

In addition to the above behavior, you will also notice green and red lines underlining some of the options on each page/tab of the Internet Settings window. After a quick search online, I luckily found another forum that explained the behavior. The green lines are settings that are “enabled” and will be pushed to clients when the policy is applied. The red lines are settings that will be ignored when the policy is applied, even if they are configured within the GPO. So the explanation for this behavior is essentially to be a fail-safe so that administrators don’t inadvertently push a setting that they weren’t intending to push. So for example, if you wanted to change the behavior of the startup setting but you do not want to change the home page, that can be achieved without overwriting the client’s home page setting (see example below).

So now that you understand what is happening, how do you actually turn on/off these settings?  There is no help or indication of how to do this within the GPO window.  The answer is quite simple.  You use the F5, F6, F7, and F8 keys as follows:

• Press F5 to enable all visible settings
• Press F6 to enable only the currently selected setting (without making changes to any other settings)
• Press F7 to disable only the currently selected setting (without making changes to any other settings)
• Press F8 to disable all currently visible settings.

So lets say on the above window that you wanted to enable only the home page setting.  You could tap the F8 key to turn off all settings.  Then click inside the homepage text box and tap the F6 key to enable that setting by itself.  You then should see the red/green lines shown as below. 

With the above window, only the homepage will be pushed to clients.  Any other settings, even if configured in this window, will be ignored.  Keep in mind, the F5-F8 keys only affect the settings in the current view.  So you can customize each tab with what is enabled/disabled without affecting any other tabs.

This information was found on the Microsoft TechNet Blog.  The link to the specific article is https://blogs.technet.microsoft.com/grouppolicy/2008/10/13/red-green-gp-preferences-doesnt-work-even-though-the-policy-applied-and-after-gpupdate-force/