I live in brisbane also and ive seen so many different coloured coastals here its not funny. infact its hard to find two that look alike.
The only exeption I seem to notice is that the carpets up in the higher altitudes like Mt Nebo and Mt Glorius all seem to be the more black and white markings. I figure this might be to the fact that there environment is so much cooler and the darker colours help with thermo regulation.
I have probably seen (including dead ones) 5 or 6 carpets from Mt Glorius and they were all very similar in colour. I have seen around the same amount around brisbane city and on the coastal areas and were all quite different.
Something else thats interesting was that in Goondiwindi where I lived for a few years, I seen around say 10 carpets, and they all looked almost identical in colouration and pattern, no variation at all.
Probably has alot to do with the different environments in different locations. Brisbane has scrubland, wetlands, coastal swamps, open fields and woodlands and semi rainforests... so there could be many different colour variations to suit the different environments in such a small area. Mt Glorius is a cooler and more specific forest environment and all the carpets from that area look similar. Out in Goondiwindi there is only one type of environment as well, plain open woodlands, and all the carpets look similar from there as well.
I could be wrong, but it makes scence to me... a different environment, a different colour/pattern to suit that environment, and the Brisbane area has many different environments within a very small area, so many different coloured carpets.
And if you think about the colours that represent most localities they make scence. Jungles are black and gold, perfect camoflarge for a rainforest, murry darling carpets are greys and muddy browns which is great for the grey clay type soils in the murry basin, alot of carpets in the brisbane lowland and coastal areas ive seen are a greeny colour with little black, goes well with swampy grassy coastal areas where ive seen them. Bredli (if you consider them a carpet) are red or orange, great for red sand and sandstone. Mt Glorius carpets are black and white with some yellow and also suits a forest surrounds and climite with lots of black to help with the cooler mornings.
Im sure alot of colours come about just from genetics and which two animals breed, but on the whole its the individuals that suit the environment best that survive and breed, and thus pass on their genes and colours. So a trend in colouration in different environments evolves.
just my thoughs, love to hear others. Has anyone seen different coloured carpets from the same environment???? not area! but the same specific environment.. like 2 different colours from the same swamp, or hill etc.?????