Expose preferred gradient color stops in configure

configure.ac

@@ -64,6 +64,12 @@ AM_CONDITIONAL(INSTALL_FALLBACK_LOGO,  [test "$logofile" = $datadir/plymouth/biz
 AC_ARG_WITH(background-color, AC_HELP_STRING([--with-background-color], [background color used by boot splash plugins]),background_color=${withval},background_color=0x3a362f)
 AC_SUBST(background_color)
 
+AC_ARG_WITH(background-start-color-stop, AC_HELP_STRING([--with-background-start-color], [first color stop in background gradients used by boot splash plugins]),background_start_color=${withval},background_start_color=0x807c71)
+AC_SUBST(background_start_color)
+
+AC_ARG_WITH(background-end-color-stop, AC_HELP_STRING([--with-background-end-color], [first color end in background gradients used by boot splash plugins]),background_end_color=${withval},background_end_color=0x3a362f)
+AC_SUBST(background_end_color)
+
 AC_OUTPUT([Makefile
            src/libply/Makefile
            src/libplybootsplash/Makefile

src/splash-plugins/fade-in/Makefile.am

@@ -11,7 +11,9 @@ plugin_LTLIBRARIES = fade-in.la
 fade_in_la_CFLAGS = $(PLYMOUTH_CFLAGS)                                        \
                     -DPLYMOUTH_IMAGE_DIR=\"$(datadir)/plymouth/\"             \
                     -DPLYMOUTH_LOGO_FILE=\"$(logofile)\"                      \
-                    -DPLYMOUTH_BACKGROUND_COLOR=$(background_color)
+                    -DPLYMOUTH_BACKGROUND_COLOR=$(background_color)           \
+                    -DPLYMOUTH_BACKGROUND_END_COLOR=$(background_end_color)   \
+                    -DPLYMOUTH_BACKGROUND_START_COLOR=$(background_start_color)
 fade_in_la_LDFLAGS = -module -avoid-version -export-dynamic
 fade_in_la_LIBADD = $(PLYMOUTH_LIBS)                                          \
                     ../../libply/libply.la                                    \