Here's my approach to colour...
I always work on the theory that I am trying to tell a convincing lie to a fish who mistakes the lure for something edible(or something that at least requires a strike).
So I need enough colour/contrast/shape/size/splash/ speed/ to be the most convincing lie.
As an example in dirty water along the coast, big poppers, contrasting colours, big bloops, slow retrieve. So maybe big ebipops, bigheads etc
If in still clear water around the offshore islands, smaller lures natural/neutral/hard to see colours/ faster retrieve, maybe neutral stickbaits?
The barramundi fishery has gone a long way with colour. The legendary gold bomber is black back gold sides, I think the reason it works so well is its mostly used in low turbidity tannin stained water so the black and gold become quite hard to see and there is enough movement and size to be detected but not enough vision to be proven as a lie. As the water becomes more turbid, contrasting, strong blotchs or bars (like the elton John) seem to outfish gold bombers, as the colour is unlikely to be seen as a lie.
I also think colour is one of the least important variables in lure presentation. Much rather have a good lure in dodgey colour that vice versa.
