So here I was in search of understanding Gradient Maps in Photoshop better. Once upon a time all I used was Photoshop. It was my right leg, I couldn't do photo editing without it. Somewhere along the way I took the time to actually learn & understand Lightroom & then I ran off with that new sweetheart & left Photoshop abandoned. But I'm coming to point where Im getting good enough in both to appreciate that you really need them for different things & to use them when you do.
In Lightroom I can use Split toning, Camera Calibration & many other things to affect color. I wanted to use Photoshop for some important work but since I hadn't used it for so long I wasn't sure how to achieve some of the same coloring in my photos that I had been getting using Lightrooms tools.
Rather on accident I came across Gradient Maps in Photoshop. I knew it was awesome & that I needed to understand how to actually use it. And after watching several videos to fully comprehend it's abilities I come to you with this simple news: this is your color god. Know him, love him & praise his grace. He will be good to you & your photos. I also realized that before learning about this today my methods have been somewhat primitive. Much like a caveman hitting rocks together to create fire when I could have grabbed a bic lighter & just moved on with my life. But in case you reach confusion at the same point I did let's discuss the difference between gradient & gradient maps because the following video didn't.
A gradient is going to apply the chosen color over the image from left to right top to bottom etc etc....however you set it. It wont care about what it's coloring. Its like a kid with a sharpie & wall. Or two crayons & the lines in the coloring book don't matter...there are no borders. Green for lots of things, maybe some on the face & let's add some purple too. There's no rhyme or reason. Which works for some pictures, but very few. Now Gradient Maps however, knows whats up. He puts color on your photo honoring the tonal range. So where a gradient would paint a shadow, midtone & highlight purple the gradient map will only paint either the shadow, midtone or highlight purple & then you can select a different color to affect the next tonal range. What you get is a much more accurately colored photo, with dimension, versus a flat colored picture that is sure to end up on someone youtube channel as a "Your not a Retoucher" videos.
So in this video you'll see all the different tools in Photoshop showing how you can affect color & you'll see that Gradient Maps reins superior. And not to call out the other tools, they certainly have their functions but limited ones. Learn it, love it, use it.