change clear color
diff --git a/progs/trivial/line.c b/progs/trivial/line.c
index ff18f07..93f10b8 100644
--- a/progs/trivial/line.c
+++ b/progs/trivial/line.c
@@ -40,7 +40,7 @@
    fprintf(stderr, "GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
    fprintf(stderr, "GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
 
-    glClearColor(0.0, 0.0, 1.0, 0.0);
+    glClearColor(0.3, 0.3, 0.3, 0.0);
 }
 
 static void Reshape(int width, int height)