Code for a master command button to change the backcolor of multiple command buttons?

I have multiple command buttons which change their backcolor to green when pressed as a visual reminder that certain tasks have been completed.
When the entire project is completed, I would like to press a master command button to restore all the other command buttons backcolor to the default grey.

I am using excel 2003 with the command buttons from the control toolbox and entered directly on a spreadsheet.

Thanks

Panttherm5

Mike, Thanks, your code works well on a single command button.
I really want a master command button that when pressed changes the backcolor on 25 other command buttons simultaneous .
I can repeat your code 24 times in the command button1 code window and change the command button number from 2 to 24 to achieve this.
I was wondering if there was a simpler way to do it.
Thanks
Panttherm5