I want to change table border color

[MikeInToshx]

U dont have a border color assigned to your .thead.

Add this code between .thead {}:

 border: 1px solid #fff; 

Change #fff with your color.

Edit
Oh the background.. U said the border color.
Your .thead has an image as background which is green. If u want to change it then ull have to make a new image.
Or if u want a solid background-color delete this line:

url(../../../images/mop/navbar.png) top left repeat-x