The pacman is an alarmingly beige colour...

[Drayvan]

Are you able to get a picture of him? Sometimes they change colour for various reasons but is generally nothing to worry about. The only thing I would be concerned about would be if he's doing it because he's too dry/cold and has started to estivate and covered himself in dry layers of skin, which lightens their colour a bit.

This is the same frog about a week apart!



As for the questions (sorry if I miss any!)
The heat pad wont crack the glass if it is thermostatted (im not sure thats really a word...o.O lol) so it doesn't get too hot.
At 6 months I feed them every other/every 3rd day usually as much as they will eat. I don't really give mine rodents so can't comment on the frequency of those but i'd definitely drop the goldfish completely. Calcium and D3 I give once a week, vitamin powder every other feed should be enough. This was posted in a thread a little bit further down from this one which seems to be a good guide http://www.frogforum.net/showthread.php?t=26121 as for pooping, it generally depends on how much and what they're eating. Mine go once every 3 weeks/ a month at around 6 months old, my adults go a little longer.

Hope that helps a bit!