[codex] Green tint compensation controls

README.md

@@ -65,7 +65,9 @@ greenfix
 The UI provides:
 
 - A connected display output selector.
-- Sliders for red gamma, green gamma, blue gamma, and brightness.
+- A reference image panel with a color chart and photo reference.
+- Large green-tint compensation, warm/cool trim, and brightness controls.
+- Advanced red, green, and blue gamma controls for fine tuning.
 - Apply, Save, Reset, and Quit buttons.
 - Visible status and error messages.
 
@@ -188,6 +190,10 @@ Use Reset in the UI or run:
 greenfix --reset
 ```
 
+Saved settings show in the UI but do not affect the screen
+
+Open greenfix again after saving, or run `greenfix --apply-saved`. The UI now applies saved settings on launch; if it cannot, the status area shows the `xrandr` error.
+
 Saved settings do not apply after login
 
 Check that `~/.config/autostart/greenfix.desktop` exists and that `greenfix --apply-saved` works from a terminal.