use strict;
use warnings;

while (<DATA>) {
    s/\[image=([\w\.]+)\]/<img src="$1">/;
    s/\[color=([\w#]+)\]/<font color="$1">/;
    s/\[link=([\w:\/\.]+)\]/<a class="my_link" href="$1">/;
    print;

}
__DATA__
Hey have a look at this [image=var.jpg]
Insert a [color=#99CC99] [link=http://www.perlmonks.net] to the site