You can optimize the performance of the Observe and Control feature by setting the observed computer to Thousands of colors in the Displays preference pane. This achieves the best refresh rates when observing and controlling.
To change the color depth at the client computer, follow these steps:
You can also follow these steps remotely while controlling the client via Apple Remote Desktop.
Note: If you are using Apple Remote Desktop over a dial-up or ISDN connection, you may wish to use Preferences to choose black and white instead of color.