Easy. Use tables. Echo your favorite php variables to set the widths.
<table cellpadding="0" cellspacing="0" border="0" bgcolor="red" width="25%"><tr><td><font face="arial,helvetica" color="white"> 25%</font></td></tr></table></table><BR>
<table cellpadding="0" cellspacing="0" border="0" bgcolor="red" width="50%"><tr><td><font face="arial,helvetica" color="white"> 50%</font></td></tr></table></table><BR>
<table cellpadding="0" cellspacing="0" border="0" bgcolor="red" width="75%"><tr><td><font face="arial,helvetica" color="white"> 75%</font></td></tr></table></table><BR>
<table cellpadding="0" cellspacing="0" border="0" bgcolor="red" width="100%"><tr><td><font face="arial,helvetica" color="white"> 100%</font></td></tr></table></table><BR>