Ha! I remember the collapsible water bladder now that you mention it! The ones we had in my last unit were straight olive drab but seeing those photos sparks some dim memory in the decaying corners of my mind!
Come to think of it, half the hootchie carriers I saw were olive drab as well.
The material used for those hootchie carriers was utter crap and I'm pretty sure most infantry guys didn't bother carrying it, just one more item of dead weight.
But yeah, as for camo
clothing, Australian troops basically had sweet FA until the DPCU was issued and it's ironic that before then, the only items of equipment that did get any sort of cam where small bits of kit that were not common use items.
But as for Cold War era cam uniforms, there's quite a few patterns I like but in terms of coolest, for me I'd choose the 1970s South African Police camo, examples of which can be found in it's various incarnations on Camopedia, here, the last quarter of the page.
http://www.camopedia.org/index.php?title=South_Africa
Generally, it looked like this (again, courtesy of Camopedia)
or this
