One way to ensure that you always see all of the text, is to strip the colours from the text. This can be done by issuing the command
this would strip the colours from any and all text that you receive (it will not effect bold, reverse or underlining)
Alternatively, you could use
echo $chan $strip($1-,c)
Which, in my opinion, is unnecessary, as both do the same thing. The only advantage to using the second one, is that you can make it specific to the channel, nick and/or text being received.