Funny you should say this but today our 9 month old beardy (female) started going through a second phase of looking ill like this. Her beard turns very dark, she doesn't move, sleeps all day, ignores her locusts (which she relishes normally) and even turned down her piece of banana (which she goes nuts for as a weekly treat). She has also pooed in her viv (where she was laying because she could not be bothered to move), which she never does and normally saves it until we take her on her daily consitutional to the bathroom sink. Lastly, I have only ever seen her drink twice in all the time we have had her. The first was the last time she went like this (about three months ago) and today, when i dripped water on her head and she lapped it up as it fell over her nose. She even lapped up the puddle it made in front of her.
Now, the common denominator in all this is that, both last time and this, her throat and beard area look like they are about to shed. She puffs up her beard and even sleeps with it slightly puffed. So she could probably be mighty uncomfortable and a little down in the dumps. Last time it lasted about 48 hours then she was back to normal.