7
           
            
                
     
    
    $img_number = imagecreate(
275,
25);
-> this pair represent the 
X , 
Y lengths
$backcolor = imagecolorallocate($img_number,
102,102,153);
$textcolor = imagecolorallocate($img_number,
255,255,255);
-> these tupples are hex-colors (255,255,255=white;0,0,0=black)
And if you wanted to ask: the border is a style attributed to the img tag: 
style="border:1px outset #000044; vertical-align:middle;" Having an option to select something like this to appear, would definetly be a nice thing! 
developers 