fix(app): Propogate color

In clap-rs#2851, we moved color from an AppSetting to function (with some
tweaks in clap-rs#2907).  When doing this, we documented `App::color` to be
equivalent of `App::global_settings(Color...)` but never actually
propagated it.

We are now propagating it.  A test is added to ensure that no matter
how we store the color choice, we continue to propagate it.  This
required exposing `App::get_color`.

src/build/app/mod.rs

@@ -1045,9 +1045,9 @@ impl<'help> App<'help> {
     pub fn color(self, color: ColorChoice) -> Self {
         #[allow(deprecated)]
         match color {
-            ColorChoice::Auto => self.setting(AppSettings::ColorAuto),
-            ColorChoice::Always => self.setting(AppSettings::ColorAlways),
-            ColorChoice::Never => self.setting(AppSettings::ColorNever),
+            ColorChoice::Auto => self.global_setting(AppSettings::ColorAuto),
+            ColorChoice::Always => self.global_setting(AppSettings::ColorAlways),
+            ColorChoice::Never => self.global_setting(AppSettings::ColorNever),
         }
     }
 

tests/app_settings.rs

@@ -1216,3 +1216,16 @@ fn no_auto_version_mut_arg() {
     assert!(result.is_ok());
     assert!(result.unwrap().is_present("version"));
 }
+
+#[test]
+#[cfg(feature = "color")]
+fn color_is_global() {
+    let mut app = App::new("myprog")
+        .color(clap::ColorChoice::Never)
+        .subcommand(App::new("foo"));
+    app._build_all();
+    assert_eq!(app.get_color(), clap::ColorChoice::Never);
+
+    let sub = app.get_subcommands().collect::<Vec<_>>()[0];
+    assert_eq!(sub.get_color(), clap::ColorChoice::Never);
+}