Tell ya what I did recently - like 2 weeks ago.

I bought a 3mm sheet of green perspex for $10.00 - I used a qtr of it and cut rectangle the same size as the front of my projector 'box'.
I then re-installed my Pinbits lamp upgrade kit.

And it is mighty green again - NOT that it was THAT bad to begin with

All up - about $30.00 
$565 on Ebay and growing - U HAVE to be joking