Color mixing in Photoshop

[wofsy]

As a novice at Photoshop one daunting hurdle is learning to adjust color.  The sliders both in the raw converter and in Photoshop give the tools but they do not tell you how to analyze the color that you have and how to create the color that you want. A landscape painter would mix colors he envisioned on his palette first, then apply them to the canvas. The pink sunset could be made into  a bronze gold, that aqua reflection turned into Prussian blue.

What technique would you suggest for doing this in Photoshop?

[jjj]

Photography isn't quite painting where you can choose you colour from the get go, but you can use replace colour to change colours in Photoshop. This can be found in Image/Adjustments/Replace colour
You can also use hue slider in the raw convertor to alter a specific colour's hue, but that'll affect all areas of that colour in an image whereas in PS it can be a more specific area of the image that changes.

[Redcrown]

I would recommend the following:

1. Use Photoshop. While color adjustments can be made in a raw converter or Lightroom, the goal you describe will require extensive masking, and detailed masking is much easier in Photoshop.

2. Learn how to use the Info Pallet and color sampler points to "analyze" color. Lots of options there. RGB values, HSL, CMYK, LAB.

3. Use Curves adjustment layers (with masks) to move the values you see in the Info Pallet from their starting values to their desired values. This takes some practice and can become a bit complicated. Usually it involves setting several adjustment points on each of the separate channels. For example, if using RGB values you might have 3 adjustment points on each of 3 channels, a total of 9 adjustments. However, sometimes you can get away with only one adjustment on one channel.

Using Curves adjustments will work well most of the time, but not all of the time. Sometimes an existing color can't be easily moved to the target color because their differences are too great. With Curves adjustment layers you will "see" that problem when the curve clips on one end.

Using Curves adjustments on an image in LAB mode (instead of RGB mode) provides more flexibility. A guru named Dan Margulis wrote a book called "Photoshop LAB Color", which is the retouching bible for color adjustments. Well worth a read if you get really serious about making dramatic color changes in images.

[jjj]

Oooh, don't mention Dan Margulis here! I seem to recall he's not exactly well thought of in these parts and some of his ideas with regard to colour space not exactly finding favours amongst the technical experts. And I think Thomas Knoll [inventor of PS] being one of them

He get referenced here.

[Redcrown]

One of you is welcome, the other is not.