What they eat can and does change the colour of their wee, sometimes rather alarmingly .

99.9% of the time it's fine

In Coco's case it wasn't and we had to have her tested for a variety of things and her tests have now come back showing that she does indeed have blood in her wee BUT it's such a minuscule amount that the exotic vet isn't worried and unless she deteriorates in her general health and behaviour, she's basically been discharged.

So what I'm trying to say is; keep an eye on it. If it continues to be red but he's had nothing to eat that would change the colour of it then you may need to seek veterinary advice. But even with investigations it could very well prove to be nothing sinister - such in the case of Coco. And just as an aside, she has had red wee since December last year, and still has it more often than not, but basically there's nothing wrong with her that they can find; she just has red wee with a teeny tiny amount of blood in it, don't know why though! They've tested for all sorts, x-rays etc, everything is working as it should. Even the exotic vet doesn't know why.