Thomas Brigantino made a really useful video on dealing with color casts

[Ad Dieleman]

It took me more than an hour to figure out what the heck he was doing, but I persisted because I felt this could be a very important tool to master. I used his method on the following picture which I didn't get to my liking color-wise.

ILCE-7    FE 16-35mm F4 ZA OSS    21mm    f/9.0    1/5s    ISO 100

I used the method of the video followed by a Brightness/Contrast layer and a warming Photo Filter layer where some light signs are masked out to retain their real color. I'm not sure I'm there yet but it looks promising. Thomas showed it for interiors where you often get different color temperatures and casts in shadows/midtones/highlights and I'm sure it'll work very well there.

ILCE-7    FE 16-35mm F4 ZA OSS    21mm    f/9.0    1/5s    ISO 100

 

[NickCyprus]

Another great photo Ad and very informative link!
Although to be honest, I like both versions

 

[dbmiller]

I can definitely see where it feels like too much blue in the blue hour photo, and none in the latter - I wonder what the latter would look like with a cooling filter applied.

Took me a bit to figure out what he was doing as well. I think you could do it all in one curves layer, but separating in out makes it a little easier to understand the pieces. Which if I understand the video, is...

• Light sources from different sources may cause different color casts in the image, not easily fixed by a "simple" white balance.
• When using the eye-dropper tool in the curves layer, be careful not to pick a blown out pixel as your black or white value.
• The trick of using a grey-filled layer to find the 50% gray area was pretty neat.

 

[robbie36]

I know this guy pretty well because he does a lot of tutorials on Lumenzia (luminosity masks) which I use a lot.

However although he really knows his stuff, his videos are seriously over long.

Still he does get a triple word score for using a 'threshold adjustment layer' in Photoshop during a tutorial.

And with that here is one I did earlier...

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[Ad Dieleman]

However although he really knows his stuff, his videos are seriously over long.

Surely agree on that one. I once commented on irrelevant chit-chat in a video and he replied that he left the dry and boring tutorials to others.