I don't think the flower colour can help with ID for spath's, reason being I have driven all over East Au, and the majority of spathulata sites on the coast (easily over 100 sites I have seen) between Sydney and Cooktown are pink flowered.
Some pops, such as a few near Newcastle, Bundaberg and Cairns do have white flowered plants, but only a handful (except Newcastle where 5/7 sites had white flowers, as opposed to Cairns where 2/14 have white), if you go more than 50km inland you start to see white flowered and very few pink flowers here in Au, also as one goes further south one seems to find more white colonies.
So in summary the pink/white flowers are randomised and both abundant, both with a very large range and both with exceptions to the rule of coast/inland, however many western and southern pops seem to be more prone to turning red than coastal northern pops that even in high light can remain green in a few localities.
So when Carlton said "there are a number of pink" he was on track, there are potentially hundreds of pink localities, I am also convinced that many (such as Sydney's) may actually be mixes of the regions plants in cultivation as spathulata are one of the most common carns on the east coast north of Sydney (rivalled by D.peltata, U.uliginosa and gibba), in many localities have flowering plants year round and are readily found in the suburbs and on rd sides where seed collection is easy.