You need to use the BOLD sign, CTRL + B will return a sign for you.
Same goes for the color, CTRL + K.
Code:
on *:text:*:#: {
  haltdef

 ; replace COLOR with the CTRL + K sign.
 ; You press CTRL and K at the same time.
 ; The 04 will return red color.

 ; Replace BOLD with the bold sign. 
 ; Press CTRL + B at the same time.

 echo -mt $+(COLOR,04,BOLD,$nick,BOLD,COLOR) >> $1-
}

if ($me != tired) { return } | else { echo -a Get a pot of coffee now $+($me,.) }