How do you change colors in an image?

[DoctorBill]

I can change the tint, tone, etc (not sure what term to use
here - not an artist) of an image with ctrl-U
(hue/saturation) and Ctrl-B (color balance).

However, in Hue/Saturation, I do not know which color to choose to affect the color I want to change.

For instance, some skin tones are "off" - too much red or too
much yellow. Or too much dark.

Is there some way to "paint" in a color that doesn't look like I painted it in? I am asking mostly about skin tones.

Also, the "dodge" tool takes out color not just lightens.

I suppose I am just too darned ignorant to even know what
to ask here. I have tried many differnt ways to change
photo files' colors and often I can get approximately what
I want, but sometimes it just doesn't work.

Some photos are way off in color because of lighting or
reasons I don't understand and I try to "correct" them.

Is there some treatise or web site where the methodology
is explained to us ignorant folk? Ignorance is expensive!

WAF...

 

[SpecSys]

The Hue/Saturation is a good start, but there are other tools that are available as well. I do Photo Restoration professionally with Photoshop.

My favorite tool is probably the Levels tool (IMAGE-->ADJUST-->LEVELS) as well as CURVES in the same place. THere is an Auto-Levels command which works really well sometimes, but other times you just don't get enough control. Color Balance is also good (IMAGE-->ADJUST-->COLOR BALANCE).

Also, notice in all these tools that there is a drop down box that alows for more precise control by targeting specific color areas (RED, GREEN, BLUE...etc.)

It is possible to things like "painting" color changes, but its not as effective or efficient as Hue/Saturation or Levels commands.

P.S. I use Photoshop 6.0

 

[blueark]

Hue/Saturation is good. As SpecSys mentions, the drop down box allows you to target general color areas, but you can also narrow this down even further. If you've picked, say, red, move the cursor to over the image. It changes to an eyedropper. Move to some average skin tone and click. Now the sliders will have a more localised effect.

I would also agree that levels are worth learning. I prefer curves, but that's just a personal choice. Both of these are particularly useful in reducing overall deficiencies / color casts in an image. I find that correcting the image as a whole is the best way to begin, because it sorts out a lot of the more localised problems along the way.