hi please help me on how to change the gray background of mybb forum ?
Look in global.css under ACP - templates and style - themes - your theme
look for the body tag, and change
background: #fff;
Check Global.css under ACP and it's likely set under body.
It will look like
body
{
background: #hex;
}
change the hex value.
I can help you do this if you are struggling, HMU!