OK, presuming you want some constructive feedback here we go. First welcome to Perl - the worlds funnest language - it is ideal for tasks like what you are trying to do here. As this is relates to your code I will just mention that this task has already been done and is available via a variety of perl modules. Who cares. So it's an old wheel. You have to start somewhere and this is an interesting task.

Now to your code:

First you don't use -w and use strict which can save all sorts of headaches when your 100 liner here develops into a 100,000 line frontpage rival. For info on lots of perl godies including why you should be using strict and warnings see the links in New Monks

Now you have some typos like the lack of a $ before $bgcolor in your body tag so the user can specify any color they want but will always get "bgcolor" - I'm not sure what this renders as (probably white) but you should have picked this up during testing. When testing you need to test several options, null strings.... and see it all works.

Your user interface is sub optimal. This script was designed to run with a command line argument of the file to process - try it without. Whoops - it is now prompting the user for input with the while (<>) You can escape this with the EOF character ctl-Z in WIN32 ?ctl-D (I think) in unix.

Next your program logic flow is sub optimal. You continually prompt the user for input so you should write a sub.

Also on the logic area there are far better ways to test that a user has entered one option from a list of colors - see the code that follows.

Next your understanding of how HTML is rendered seems lacking. You need to escape literal chars like < as &lt; > as &gt; and & as &amp; like I just did here so they render as expected. Aditionally one or more spaces are rendered by HTML as a single space. Thus if you want to preserve multiple spaces and tabs as big spaces you need to escape them as &nbsp;

Next if you want to preserve the line formating of a textfile you need to use <BR> a lot as newlines in HTML are not rendered as newlines in the browser. I have shown one way to do this for fun but the easiest is to use the <PRE> </PRE> tags to wrap your text in so the formatting is preserved - you do get monospace font though.

Finally it seems you have yet to discover herepages to print out HTML. They are great. Also print is slow. Lots of prints are slower so it is often a good idea to lump everything you want to print into a string and then print the lot with a single print $string; command.

Logically the output should go to a file rather than the screen. I will leave this as an exercise for you.

Here is my version of your code with heaps of comments

Umm... feedback? well...

For first, you don't use Strict or -w, then you go on to declare your variables in an awkward way. Did you try to do my $title; instead of $title = '' ?

next, the elsif is ugly, and do you need to re-print the line each time I type it?

the while loop is unbreakable, how can someone exit that? and you might want to redirect STDOUT to a file, so one can save what he is writing quickly.

That's my 2 cents for it.