Answer:-Change LOG ON WINDOW in XP
Well as the colours used by Windows XP are expressed as RGB values (Red Blue Green), we have to establish what Lime Green's RGB value is.
To do this:
1) Right click on the desktop and then select "Properties" from the Menu.
2) On the resulting window select the "Appearance" Tab then click the "Advanced" button.
3) On the next window select "Colour " then "Other".
4) Now on the new window select a colour you like and note its RGB as shown in the bottom right hand corner of the new window.
For example I have chosen is:
R63 G270 B76 or simply 63 270 76
5) Once you have your RGB values you can close down all the open windows.
6) Now navigate to:
HKEY USERS\ DEFAULT\Control Panel\Colours.
7) The default value should be: 0 78 152
You can change this now to your chosen RGB value.
The changes will not take place until you log off.
IMPORTANT: This procedure contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs