Keri (keristars) wrote in itut,

Tutorial: Re-coloring part A - replace color

Tutorial Type: program
Skill level: intermediate
Program used: PS-CS, PS7
Notes: I used screencaps from Photoshop CS for this tutorial, but the same dialogue boxes are available in Photoshop 7 (one's on my laptop, one's on the family computer, so I checked!) - although as far as I know, there isn't a replace color feature in PSP, when I used PSP5, there was a tool that could be used with similar effects.

Goal for this tutorial: to show how color can be altered in an image through the replace color setting in Photoshop, also to explain the options

Starting Image: - this is from Getty Images and is the complete picture, simply resized to 100x100px for practicality. Use this image to follow along, or use one of your own.

If this is your first time playing with the replace color feature in Photoshop, I highly recommend using a picture with simple coloring, such as the one I am using. It is easier to see what happens with different settings, and it's also more likely that you'll have positive results, thus reducing frustration. You needn't use an icon sized image - in fact, when I was making an icon with this, I used it at full size, then reduced it for this tutorial! Unfortunately, the dialogue boxes could not be made any smaller and resizing them lost some detail, so these images are somewhat large.

The "color replace" can be found under Images -> Adjustments -> Replace Color. I may use different terminology throughout this tutorial, but this is what I will be referring to. I always want to call it "color replacement" but that's not the official wording, alas.

The default dialog box should look something like this:

1. The Selection Section
My image is on the left for reference purposes. In this example, I have used the dropper tool to choose the color I would like to change. In this case, it is the green background, where the arrow is pointing. This color is show in the top green box. That box will always be whatever you have clicked to change.

The middle box is like a mask. Everything that shows up white will change. Everything black is unaffected. As you can see here, there are three white spots which correspond exactly to the green my dropper tool picked up.

The "fuzziness" slide is similar to the "tolerance" slide on the magic wand tool. By setting it to 0, you are telling it to only change the exact color in the upper box. By increasing it, you are telling it to allow variations on the color, both ligher and darker and more or less red/blue. The next two examples show what happen when you change the fuzziness.

Do you see how some areas become grey? Those areas will be adjusted only partially. It is as though an opacity filter has been placed on the color tool. The lighter the grey, the more it will be affected by the color change. Thus in example two, the girl will not be adjusted at all, and the left side of the background will only be slightly changed, while in example three, the background will all be changed and the green tints in the hat will change slightly.

2. The Replacement Section
The next example shows what happens when you change the slides in the bottom half of the box, using the selection settings from the last example.

As you can see, these work like the Hue/Saturation settings. The top slide changes the hue. The color you selected will always be in the middle, in this case green. The opposite of green is magenta, therefore when you go to the edges, it becomes more magenta. The middle slide changes the saturation. All the way to the left will remove saturation, as in greyscale. All the way to the right will add saturation. The bottom slide adjusts luminosity. The left is more black, the right is more white.

This is example is good because you can see how, by choosing a green on the far right of the image, the left side is changed differently because it is not as similar to the selection color - it is grey instead of white, so the adjustment is on a "lower opacity" (so to speak). Move the slides around and see how they affect the color.

3. Replacing Color in a Specific Area

You can also replace specific selections. The marching ants indicate I have selected the girl's hat to replace the color. In the replace color box, I used the dropper to choose a khaki tone in the hat (right about where the arrow points) - but it's also present in her face! Note the difference in the central box from when we selected a green in the background. However, by using the selection, when I used the replacement slides, only the hat was affected.

4. The Selection Box Image

This example is, unfortunately, slightly out of order. It would have done best up in the first section, but I forgot to take a screencap until after I had changed the hat, and I didn't want to be confusing because of that.

At any rate, this shows how the two radio buttons work. The "selection" button causes the box to show similarities to the selected color in greyscale. The "image" button shows the original picture, where you selected the color. If you're trying to compare a new color with an old, this works really well in conjunction with the "preview" (which I've been using all along). However, for knowing how much color is being replaced, the "selection" button is my preference.

5. The Dropper Selection

I wanted to brighten the girl's skintone, so that it wasn't so grey compared to her hat. However, by selecting part of her face with a high fuzziness, I also ended up changing the hat and shirt colors, which I didn't want! But the detail was very small and I didn't want to take the time to use the freeform selection tool when the colors are so similar. What did I do? I used the Dropper +. Like with the various selection tools in the basic menu, you can use the plus and minus droppers to add and subtract shades from your selection area - but be careful, because using the fuzziness slide might make your efforts nill.

As you can see, by using a relatively low fuzziness and selecting portions of her face AND hand, I was able to adequately adjust her skintone.

6. Where To Select?

As you saw above, using color selection from the far right of the background made it look jagged. I could have used the dropper + tool, but there's an even easier way to fix the problem.

I instead selected from a medium shade of green, halfway between the colors on the left and right (one is less saturated and more luminous than the other). I could then adjust the fuzziness until just enough was changed. TIP: to make the highlights in her hat look right, I selected a tiny portion of the white on the right, to make it more blue than green.

The result:
Result #2:

Note that #2 is the same as the first icon but with only the background changed, then duplicated on "overlay" at 50% opacity. I include it here to show how changing color can create different moods in the same picure.

NEXT TIME: Re-Coloring Part B - Gradient Maps! With both results 1 and 2 from this tutorial as examples. Yay!
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