There’s just as many ways to fix a colour cast as there is to skin a figurative cat. Here’s a way to do it using just one layer and it takes about 30 seconds.
Basically, you duplicate your layer then go to filter - blur - average. This will give you one solid colour that is in fact your colour cast. To use this invert this layer using cmd-i. Set the layer to soft light and tweak down the opacity to the level you need.
Quick and easy!
Have a question, feel free to drop me line.