Correcting Skin Color / Skin Tones in Lightroom

8/12 UPDATE: In June 2012,  I released a full seminar that refines and builds significantly upon the tutorials outlined in 2009’s Skinny Wednesday series. The entire program is now available in the CMstore and includes a 193 page PDF, high-res images for follow-along editing, collection of editing videos, editing tools for Photoshop and Lightroom, skin correction flowcharts, recorded Q&A, and more. Check out more details here!

This tutorial is directed primarily at those who use Lightroom in lieu of Photoshop. There’s really no substitute for the power of curves, masks, and CMYK number evaluations — none of which are available to those who do all of their processing in Lightroom. With that said, reasonably accurate skin color corrections can be performed with Lightroom alone, and I think it’s worthwhile for all Lightroom users (even if you have Photoshop) to improve their understanding of color evaluation. Now that I’ve taken the time to figure this out, I do find myself achieving more pleasing color in Lightroom prior to export, as skin evaluations are a great way to determine proper white balance if no neutral gray exists. Let’s get into it …

Color Readouts in Lightroom vs. Photoshop

Lightroom’s color space is called “Melissa RGB” (also referred to as “bastard RGB” or “lovechild RGB,” depending on who you ask). It’s based on ProPhoto RGB with an sRGB gamma curve. It’s not really important that you understand the intricacies of the color space; what’s important is understanding that RGB numbers mean different things depending on the RGB color space in which you are working. RGB numbers applied in the Adobe RGB color space, for example, look significantly different than applying the same numbers in the sRGB color space. We’ve all seen what happens when our browsers interprets the numbers of an Adobe RGB image in the sRGB color space: we get dull, muddy colors.

Not only is Lightroom using a unique RGB color space, however — it’s also displaying RGB values in percentages … so rather than seeing R, G, B expressed as values from 0-255, they are expressed as values ranging from 0-100%. In short, anything you knew about specific RGB values in Photoshop will not translate well into Lightroom.

Let’s look at a quick example. If I sample the same point on an image in both Lightroom and in Photoshop, here’s what I get:

capture1 capture2

In this case,

79.7% R, 70.5% G, 63.0% B (in Melissa RGB)
EQUALS
228 R , 172 G, 155 B (in sRGB)
EQUALS
11% C, 36% M, 36% Y,0% K (CMYK)

Skin Color in Terms of Lightroom’s “Melissa RGB” – General Rules

There are no CMYK readouts in Lightroom, but as we discussed two weeks ago, you already know that when skin is “correct,” R>G>B (red is the highest; blue is the lowest). While values may vary from color space to color space, this relationship – Red the highest / Blue the lowest – will always hold true.

Therefore, the first thing you can do to see if your skin color is correct is to ensure that your values are coming up in the correct order:
R: highest %
G: middle %
B: lowest %

We can get a little more specific. In general,
R: Y + (15-20)
G: average of R and B
B: R – (15-20)

For example, the following values represent common Caucasian skin tones using the rules above:
* R: 80%; G: 70%; B: 60%. R is 20 points higher than B, and G is midway between R and B. That’s perfect.
* R: 86%, G: 78%; B: 70% also reflects a nicely balanced skin tone. Again, G is midway between R and B, and R is 16 points higher than B. This, too, illustrates a great relationship among the colors.

Skin Color Evaluations for Different Ages and Ethnicities

General Rules are all well and good, but not everyone’s skin is the same. How do the rules above apply to non-Caucasian skin (which is often darker and/or yellower than adult Caucasian skin) or babies (which is often pinker than adult Caucasian skin)?

You need to take what you know from past tutorials and apply it here. Reduce your blue value to create a yellower tint for Asian or Hispanic skin. Reduce your green value to create a pinker (more magenta) tint for an infant’s skin. African American skin is both darker (with more cyan) and pinker (with more magenta), so you’ll need to reduce BOTH your red and your green. If there’s interest in this, we can cover different ethnicities in more detail in the coming weeks, but you should be able to apply your knowledge of CMYK “rules” here.

Correcting Skin Color in Lightroom

Here’s a basic workflow for skin color correction in Lightroom. This is a suggested workflow only; you do NOT have to follow the steps in this order (and sometimes it makes sense to do it another way — such as when you only have to make one small adjustment). We’ll apply it in a sample picture shortly.

1) Enter Develop Module
Select your image (or set of images), and enter the Develop module.

2) Select Eyedropper Tool
Press “W” to select your white balance eyedropper. You’re not going to click anything; you’re just using it to take RGB measurements.

3) Take measurements
(As in Photoshop skin color evaluations), hover over a representative skin midtone — neither a highlight or shadow, not on the cheeks (which ought to be pinker), and not where a color cast exists (unless the entire photo has a cast due to poor white balance) Make note of your RGB numbers.

4) Move Green to Midway Point
Move the tint slider until G is midway between R&B.
* If G is too close to R, move the slider to the left (towards green)
* If G is too close to B, move the slider to the right (towards magenta)

5) Adjust Blue Value
Adjust your color temperature until R is about 15 points higher than B. In general, this means moving the slider to the right (towards yellow) to warm up the pic; if the skin is already too warm, you’ll want to move the slider to the left (towards blue).

6) Correct Brightness if Necessary
If you’ve had to move your temperature significantly towards the yellow, you may notice that the entire image has become to bright; conversely, if you’ve moved your temperature significantly towards the blue, you may have darkened the image too much. Adjust the exposure and/or brightness sliders to correct the image as desired.

7) Readjust the Green
The green may have left the midway point when you adjusted the temperature slider. Check it again, and adjust the tint slider until G is again midway between R&B.

8 ) Correct Cyan – SOME NOTES
This is the tricky part, and it’s the part where your eyes are probably the most important. To correct cyan, you adjust red, right? BUT THERE’S NO RED SLIDER. A little refresher from two weeks ago:

When a color is neutral (black, white, or neutral gray), R=G=B. Anytime you bring the R, G, and B values closer together, your color will approach gray.

When you reduce red (add cyan), you draw your red value closer to the green value, which brings the skin color closer to gray. We have no red slider here, but we do know how to increase or decrease “grayness,” right? The saturation slider, of course! When you increase saturation (or vibrance, for a lighter touch), what you are doing is effectively PULLING the RGB values farther apart from each other. In doing so, you also reduce cyan.

A little common sense will help you figure out another slider that might help here. We know that skin is primarily RED, but what color of the rainbow really comes to mind when you think of Caucasian skin? Think crayon box. Peach! And what is peach? Kind of a pinkish-yellow? Kind of a light … orange? Skin – any ethnicity’s skin – is primarily RED in terms of RGB/CMYK … but in practical terms, it’s really a combination of red and yellow, and red + yellow = orange. Therefore, you can also turn to the ORANGE slider (see the Hue/Saturation/Luminance panel in the Develop module) to fine tune your skin colors. Increase the orange saturation to widen the gap between Red, Green, and Blue; decrease the orange saturation to bring Red, Green, and Blue closer together.

With this in mind, let’s get back to the adjustments …

8 ) Correct Cyan
When we left off, R was about 15 points higher than B, and G was roughly midway between them. Next, you’re going to increase the gap between R and B to 20 points. Do that by moving up the sliders for one or more of the following (you may find that one is better than the others, or you may prefer to use a combination):
* Increase the saturation slider
* Increase the vibrance slider
* Increase the orange saturation slider (in the HSL panel)

You may find that the effect is too much. Go ahead and scale it back if you like. You do not necessarily need to use this step at all, but I recommend always testing it out to see if it improves the image. Having a 15 point gap between red and blue SHOULD result in a cyan value that is roughly 1/3 the value of yellow (in CMYK), but sometimes it leaves with you cyan that is a little high. If you increase the gap between red and blue to 18-20 points, you are almost certain have a cyan value well within the “correct” range in terms of CMYK. As always, however, you have to let your eyes be the judge.

Lightroom Color Correction in Action

Now you have all the principles and the workflow. Let’s put it into action. Here’s our original pic for today:

lrshep-1-of-1

1-2) Enter Develop Module; Select Eyedropper Tool
I’m in the Develop Module and have the eyedropper tool selected.

3) Take measurements
I’m measuring right from the middle of his forehead, which looks like a great midtone to me. As usual, note that the color of the image is not correct – you just want to pay attention to the numbers in the screenshot (my screen capture software is not color managed):

capture3

slider1

4) Move Green to Midway Point

Okay, I have R at 74.7 and B at 65.6 … The average of those is about 70.5, which means there’s not quite enough green here. Looks like I need to move the tint slider towards green. I moved it down from +6 to 0, which gives me these values (note that R, G, and B all moved — but the important thing is that G is now almost exactly halfway between R and B now).slider2

capture4

5) Adjust Blue Value
We need R to be 15 points higher than B. Right now, it’s only about 11 points higher, so we need to decrease the blue. I’m moving the slider to the right (towards yellow), from 4250 to 4619:

slider3

capture5

6) Correct Brightness if Necessary
The brightness looks fine, but I want to bring it down just a smidge (moved the brightness slider from 29 to 21). How does that affect my values? Everything got lower, but the relationships are about the same:

slider4

capture6

7) Readjust the Green
Let’s see … green is 7 points lower than R and 8 points higher than B. That’s really fine, but just for fun, I’m going to fine tune it (pulling it towards magenta to +3):

slider5

capture7

8) Correct Cyan

Where are we now? Looks like R is 14.2 points higher than B, and G is almost exactly halfway between them (7.2 from R and 7.0 from B). We need to reduce the cyan by increasing the gap between R, G, and B until there is about a 20 point difference from R to B. As discussed above, we have three options:

* Increase the saturation slider
* Increase the vibrance slider
* Increase the orange saturation slider (in the HSL panel)

Let’s try each one. I’m not going to show you the numbers screenshots (especially since the color of the image is not accurate in those). Here’s where we are presently:

lrshep-1-of-1-2

Increased saturation to +10. Numbers: R73.6, G 64,5, B 54.0

lrshep-1-of-1-3

Increased vibrance to +76. Numbers: R 73.1, G 64.3, B 53.5

lrshep-1-of-1-4

Increased orange saturation slider to +40 . Numbers: R 72.3, G 63.2, B 53.2

lrshep-1-of-1-5

Personally, I think that all of these look fine, depending on what you prefer in terms of overall appearance. I like a saturated look, but the hair is a little too orangey for me in #1 and #2, so I’m going to stick with #3 (orange saturation increased by +40). If you think it’s too much, you can pull the saturation back, but I do recommend not reducing the R-B difference to less than 15 points (we’re at 19.1 points right now).

Final Check

If you ‘re working solely in Lightroom, that’s where your color correction would be complete. To show you how far we’ve come, however, I’m going to pull the original and finished images into Photoshop, where I can take CMYK measurements and gauge our adjustments against the known CMYK rules:

ORIGINAL (with color samplers):

lrshep-1-of-1b

CORRECTED (with color samplers):

lrshep-1-of-1-5b

ORIGINAL vs. CORRECTED – readouts (see color sampler placement, above):

lrshep-1-of-1binfo lrshep-1-of-1-5binfo

You should see a big improvement in the CMYK numbers for skin above. The original had excessive amounts of cyan (more than 1/2 the value of yellow across the board) and magenta (exceeded the yellow in every sample). In the corrected version, the numbers look perfect in samples 2 and 3 (yellow slightly higher than magenta; cyan 1/3 or less the value of yellow), and while the cyan is a little high (by about 4 points), it’s not ridiculously far off. We’re in a little bit of a tough situation, too, in that the shadows are starting to look a little yellowish orange, and we can’t mask in Lightroom — so if we were to increase the saturation even more (orange saturation or overall saturation) to reduce cyan in the midtones, I expect the shadows would look even worse.

Overall, Considering that we aren’t actually able to work with CMYK numbers in Lightroom, I think this came out looking pretty good. Furthermore, all we’ve done is to correct for skin — I think I took the brightness down a little too much, so I’d probably go bump that up with the adjustment brush (I think the face needs to be brightened more than the rest of the image), plus maybe deepen the blacks a bit, and increase the saturation of the greens and blues …. As for skin, though, I think we’re in pretty good shape.

I’m just beginning to explore skin color correction in Lightroom, so I’ll keep you updated as I discover more down the road, but this should get you started. Have questions? Find something that works better? Let me know in the comments!

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11 Responses to Correcting Skin Color / Skin Tones in Lightroom

  1. John Martin says:

    Thanks for this. I’m color blind (not horribly bad but it makes skin tough.) I also used to work in offset printing so I know CMYK very well. Switching over to using lightroom instead of photoshop was great for productivity but played hell on my skin tones. So this article really helped.

    I’ve found a quick fix for skin that has helped me and it’s along the lines of your technique (although adjusting the saturation to spread out the red/blue channels completely escaped me.) What I do is adjust it as best as I can to get “close.” That is R>G>B. If you do this and use the hue targeted adjustment tool only the green channel changes. Green MUST be higher than blue or it will move both. Then it’s just a matter of draging up or down until your Green falls where it needs to.

  2. admin says:

    Love this tip, John! That makes perfect sense, but I hadn’t thought of it. Definitely going to try it out. TFS!!

  3. sridhar says:

    Thanks a lot.. it’s a superb tutotial. Helped me a lot

  4. This is going to be a lifesaver!

    Gathered photos of the same event from a number of cameras and was having terrible trouble getting them all to sync up color. Since I only really care about the skin color, this will really help.

    Thanks.

    Jonathan

  5. Emilio says:

    Thank you so much. Lately ive been having problems with skin color, this tutorial is the best and simplest one on color correction.
    Congratulations!

  6. Great website , love the template. Seriously considering migrating to this cms now!

  7. I see a lot of good content here, what template do you use ?

  8. Excellent article i am sure that i will come back here soon

  9. You made some good points here.Keep us posting. What template do you use in your blog

  10. bingo uk says:

    Very interesting website, but you must improve your template graphics.

  11. Pingback: Teen: Split lighting in the evening

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