fix color bias behavior

wayvr/src/backend/openxr/overlay.rs

@@ -215,8 +215,10 @@ fn try_update_color_scale_bias(
         next: std::ptr::null(),
         color_bias: Default::default(),
         color_scale: xr::Color4f {
+            r: 1.0,
+            g: 1.0,
+            b: 1.0,
             a: alpha,
-            ..Default::default()
         },
     });
     *color_bias_khr = Some(new_item);