Panthers will not be changing there home jersey. 2011 was the first season in that design (I know it's not very different to the previous seasons jersey, but it was different enough for the NRL to consider it a new design). Source: Panthers merchandise and membership manager.
The Alternate jersey is still up in the air. I can confirm that it won't be teal. It may be the white jersey we wore all of this year, although that was supposed to be a one off "White ribbon campaign" jersey, which we wore forced to wear more often than expected. The white jersey has proven to be a very strong seller and very popular among fans. Next years 'members jersey' is based on that design, I'll try and find a link. So it's a very good chance.
But Penrith being Penrith, there is always a chance they'll keep the white jersey as a "white ribbon" jersey and members jersey, as well as create a new away jersey just so that they can boost sales. fingers crossed thats not the case.
Heritage will be the liquorice allsorts agains.