Thanks for the replies Gomer and Craig. Looks like so far we have one vote for yellow and one vote for normal red. I always love a mystery.
Gomer, as far as I have investigated we only have normals here, and because of their high cost (over AUS$700/pair) not many people keep them. They are usually imported from Belgium, and I would imagine that yellows and fawns are available there so it should be possible to get ahold of those mutations too (if you have a fat wallet). I would like to produce a nice fawn yellow so if this bird is a true yellow then I'm part of the way to my goal. When I return home and have much more land available I plan to concentrate on the conservation of endangered species, so mutation finches won't be a major part of my interests.
In that link, all your birds seem to have an unusual colour to a normal.
Craig, of the nine Painteds shown at the top of that webpage, six are imported stock (two separate imports over several months) and were photographed on the days I received them (so a few days after they arrived in the country). If they have an unusual appearance it may be with the Belgium stock. The illumination I use to photograph birds may be changing their appearance slightly but I think the colours in the photos are reasonably close.
It's still possible that the juvenile Painted I posted about may be affected by its diet, but the same diet did not affect my other Painted juvenile of the same age, nor my other six imports. Regarding diet, I think I have most bases covered: a good quality finch seed mix (has around 8 different seed varieties), commercial egg food (Witte Molten
http://www.wittemolen.com/en/products/dry-eggfood), sometimes with a trace amount of vitamin D3 added (
http://www.nekton.de/en/product-reader/ ... a-132.html), mineral block, cuttlefish bone, oyster shell powder, charcoal powder, greens about once a week and a touch of Nekton S vitamins
http://www.nekton.de/en/product-reader/nekton-s.html in their water about once a fortnight. I can't imagine anything in the above that could be causing a colour change in one individual but anything is possible I guess.
I have another six youngins', some of whom are starting to colour up, so it is going to be interesting to see how they turn out.
Regarding your orange-rumped Diamonds Craig, it's troubling that someone would feed birds only a single seed variety; if I had to eat only peas for the rest of my life I think I would change colour too
