I have been already trying many approaches that would catch for me the following things: 
-41
-55
-jj
1au
24u
36u
I have written the following regexp: 
if ($MType =~ /-[45][15j]/ig ||
    /[123][a46]u/ig ||
        /7[9l][hb]/ig) {
    print "\"red\"";
} else {    
    print "\"#CCFFCC\"";
}

[download]
All I'm getting is jj4. I have no idea where this comes from.

This is how I interpret my regexp: 

1 regexp:  If the first char is '-' and second is 4 or 5 and third is 1 or 5 or j OR
2 regexp: If the first char is 1 or 2 or 3 and second is h or b and third is u <...> and so on.
Where is my logic flawed? I need some enlightment, PLEASE!

In reply to Regexp experts, come to rescue! by bman

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