Change the Display Settings in MAC OS 10.4:
1. Open System Preferences and then click the Displays icon.
2. Click the Display button to bring Display settings to the front (if they aren’t shown already)
3. Choose a resolution on the left side of the screen
4. Use the Brightness slider to adjust the display brightness
5. Adjust the colours setting and a refresh rate as required
6. Close the window to save the changes