Wednesday, March 10, 2010

A Little Color Theory - Part II

by SandWyrm

The Munsell Color Wheel

In "A Little Color Theory - Part I", I talked about the color primaries, pigments, and how we perceive the colors we see around us. So now it's time to build on that information and learn how to properly mix the colors we want.


First, A Little History

Back in 1991, when I went off to art school, I was taught the Munsell Color System. Which was developed in the 1930's as a way of trying to formally explain what traditional painters had been doing on their own for hundreds of years. This system used Red, Yellow, and Cyan (called "True Blue" by my instructor) as the color primaries. That color wheel (shown above) is very traditional in that it compresses the Cyan/Blue and Magenta ranges while extending the rest. But it's still an advance over Newton in that it does at least include Cyan and Magenta. Even if they're toned down a bit.

This, by the way, is the color wheel that most of your Citadel colors are based on. There are newer paints out there that have a more modern selection of colors. But you'll have to visit an art supply store to get them.

Professional Printers used to use the Red-Yellow-Cyan primaries, but they've since switched to Cyan-Magenta-Yellow, with Black added for contrast. If you ever wondered why printing in the 90's and 00's looks so much more vibrant that printing from the 60's, 70's, and 80's, that's one reason why. The CMYK color model produces a much wider range of colors than the old RYBK model.

Now, compare that traditional wheel shown above to the color wheel that a computer graphics artist like me uses. Which is based on mixing Red, Green, and Blue light.
The RGB/CMY Color Wheel

Pretty vibrant eh? You'll notice that Red, Green, and Blue are equidistant from each other, and so are Cyan, Magenta, and Yellow. This is the color wheel I'll be using for the rest of these articles. As it matches up well with both the print and computer graphics industries. It's also continuous, as each Hue smoothly mixes into the colors next to it. So you don't get any strange, sudden Hue transitions, like you do with the old color wheels, where purple is sitting right next to Magenta with nothing in between.


The HSV Color Model

Now let's discuss the HSV color model.  HSV stands for Hue, Saturation, and Value. Let's define these terms:

Hue

A color's hue is it's position on the color wheel. Blue and Yellow are both Hues, for instance.

Saturation

This is the intensity of the color. Maximum Saturation can be thought of as the purest form of the color as it appears on the color wheel. Minimum Saturation is pure Gray.

Value

This is the lightness or darkness of a color. Maximum Value is pure White. While Minimum Value is Pure Black.

Graphically, it all looks like this:


In this example we've selected a point on the color wheel (Red) of pure color. Which is shown on the tip of the triangle to the right. At the top and bottom of the triangle we have white and black. Representing our maximum and minimum values. Between these 3 points, we have every possible tone of Red. The pastel Reds are up near the top, and the Brownish Reds are down near the bottom.

Here's the same chart for Green:


And another for Yellow:


At the top of the Yellow chart, we have the shades of teeth and bone. Which are just high-value shades of Yellow. At the bottom, we have our Yellow-Browns.

So as you can see, every color you see around you is just a shade of a pure hue mixed with white and black. This means we can show the entire range of visible colors as a 3D shape made up of these Saturation/Value triangles combined with the Color Wheel. 

Like this:


You can mix any color then by first mixing up it's pure form, and then adding White and/or Black to get the specific shade you need.

So with all that in mind, here's some color mixing tips.


1) You can't have maximum Saturation and maximum Value at the same time. Adding White or Black will always Desaturate your Colors.

Everything is a trade-off. That's just how it is.


2) To get a more realistic or neutral color, like say a Khaki version of Dark Angels Green, you need to add both White AND Black.

Most people just grab a pure bottled color and add white OR black to it. But that means that you'll only ever travel the top and bottom edges of the Saturation/Value triangle. Adding Gray gets you into the mid-tones, where the more realistic colors reside. It also lets you mix browns using Reds, Oranges, and Yellows.

Plus, most colors in the world around us aren't as saturated as the comic book style that tends to be popular with GW minis. I like that style myself, but if you want a more realistic look, try adding Gray to the basic GW colors. When I say Gray I mean White + Black, not Space Wolves Gray, which is actually a light Cyan-Blue.


3) Make Sure That You Shade Within The Same Hue.

Here's a pic of my General and his Advisors:



They look pretty natural, right? That's because I start with a base color and apply 2-3 lighter shades on top of it to pick out the lighter details. To get those lighter shades, I mix white with my base colors.

Now here's some Space Marine Minis from the GW catalog:


They're well painted, but look a bit odd. Why? Because whoever painted them used Ice Blue to highlight the Ultramarine Blue he used on their power armor. But Ice Blue is a light Cyan, not a Blue. So they look oddly electrical instead of natural because of the difference in Hue.

This is a long-standing problem with all paints, by the way. The actual colors of the paint will never match up right with the names given to them because there's so many different color wheels and color traditions floating around in the art world. So learn to look at the paint, not the label. Especially when buying tube paint. Take off the cap and look because the printed color shown on the label won't match up either. You have to use your eye to look at the paint itself.

Here's a mini from the BoLS lounge that has the same Hue-clash problem:


The same goes for mixing Snakebite Leather and Dark Flesh. Snakebite leather is a desaturated mid-tone Yellow. While Dark Flesh is a desaturated Dark Red-Orange. Be careful of the flesh toned paints as well. As you don't want to use a light desaturated Yellow to shade a desaturated mid-tone Red. Or people will look at your minis strangely. They may not be able to put their finger on what's wrong, but it'll look odd to them.

So, unless you have a special effect in mind, try and stay within the same Hue by mixing your own custom shades. Or, if you want to add in a bit of color, say yellow + white for your lighter tones, then be sure to add that color to ALL the lighter shades you use on the model. Not just one like these models do. That way it'll look like the model is standing under a colored light, rather than a  radioactive skin condition. :)

To aid in this, you should buy some empty paint bottles at your local hobby store and mix up large batches of your commonly used shades in them. This way you'll only have to actually mix paint a few times a year or when you're painting something unique. I have pre-mixed shades for all my Tallarn colors.


4) Make Sure That You Use A Full Range Of Values.

Here's a mini from Admiral Drax's blog that's quite well painted technique-wise, but is very dark overall, making it look muddy and indistinct:


And here's some Marine Models from a recent local tourney that, in keeping with GW's strange new dark style, have the same problem:


The reason that the minis in both of these pics don't "pop" is that they have (intentionally or not) been painted using only a small portion of the overall value range visible to the human eye. It's as if you took one of the Hue/Saturation triangles I showed you above and cut it in half horizontally, using only the bottom half to paint your figures. Few, if any of the colors used rise above 50% in value.

Here's a comparison pic showing what my minis would look like if I painted this way instead of with a more full value range:


So what's the reason so many minis turn out this way? There are a couple.

a) Most People Use Black To Undercoat Their Models

GW always tells everyone to do this, but I can't fathom why. Black sucks the life out of your colors and makes them darker than they otherwise would be. Use White, Gray, or Brown instead. They'll preserve your colors better and are easier for the lighter paints to cover.

Personally, I use Gray spray enamel with a brown ink or Devlin Mud wash over it. This is what my undercoated models look like before I apply any colors:


The brown ink accentuates the model's details while not overpowering the colors. The raised bits receive less ink and therefore start off about 40% brighter than a black undercoat would be. The details are also much easier to see this way.

When I paint, I then start off with the base color for the clothing, skin, or whatever. Being careful not to paint into the brown cracks of the model where I want to accentuate the model's details. I then come back with 2-3 lighter shades of the same color to make it pop.

b) Most People Use Saturated Colors With A Wash Applied Over Them.

If you start with say, an Ultramarine Blue or Blood Angels Red, and then apply a Devlin Mud wash over them, then you've just put yourself in the bottom half of the Hue/Saturation triangle. To lighten back up, you'll need to do some dry-brushing or shading work using the original color plus at least one lighter shade to get back up into the mid-tones.

So if you only want to throw a wash over you model and call it done, you'll need to paint your initial colors on brighter than you want them to look when you're done. That way the wash won't pull you down into the dark tones.

Or, if you like dark-colored models, you can make sure that some detail on them is light-toned. Which lets your viewer know that you MEANT for the rest of the model to be that dark. :)


That's It For This Round

My next post on color will talk about how to select effective color combinations that not only look great, but can evoke specific moods and feelings in your viewer.
On To Part III...

15 comments:

  1. Nice article- will have to think about it when I start my next round of painting.

    ReplyDelete
  2. Another great post. I've always used white primer, as I've felt it is easier with the lighter colors. I had to learn to paint lighter before the wash, and you can tell the point where I learned that with my troops, there is a shade difference.

    I am trying to learn how to paint space marines. So you would say to prime white, do a dark wash, and then paint blue over that?

    And did I read that as mixing white with the color to highlight instead of using a lighter color?

    ReplyDelete
  3. Well, for Marines I would still prime gray, wash, and then paint over that. Every color I do typically has 2-3 passes with lighter shades.

    The quick way would be to paint a lighter shade of the base color and then wash that with a minwax walnut stain or some such. You lose some saturation that way, but the value is preserved.

    ReplyDelete
  4. Thanks for this. I would be interested in seeing some more of your work to compare. I have felt that my painting is too dark, like your examples. Also, my wife's uncle gave me a painting tip: for a bright green, make the base yellow and then paint a very thin blue on top. The colour will come out bright green. I haven't tried it yet. What are your thoughts?

    ReplyDelete
  5. It's worth a shot. My technique is not the only way to paint. But all good paintings use the entire value range, for instance. And control their hues.

    ReplyDelete
  6. thanks for an excellent and eye poping article on color, im currently painting orks in exactly the process you state as standard but I hope your series helps me to better paint my models.

    ReplyDelete
  7. Now that was an amazing article. I will try this new technique on my new Tau. By the way what colors did you use for your tallarns? I was considering painting my tau in a similar desert camo. Thanks and keep up the great work sandwyrm.

    ReplyDelete
  8. The base color for my guys is the old Bronzed Flesh, which GW doesn't make anymore, but can still be found floating around. You could also mix is using a desaturated yellow with a bit of red to make it slightly orange.

    My accents are done using a custom desaturated yellow-green that I mixed myself.

    ReplyDelete
  9. Another great article, just one question where were you when I thought that it would be a good idea to paint dark gray on black then wash the whole thing with black?

    ReplyDelete
  10. I have a theory on why they recommend black primer. If you prime white and then miss painting something, either from being a younger/newer painter or because of the way the mini is assembled, black looks better than white. A better painter will make sure everything is properly covered and thus it won't be a problem.

    Sounds reasonable?

    (To be fair, GW do recommend white sometimes as well.)

    Speaking of white/black, do they go with any color since then aren't "on" the color wheel so to speak? They are more the center of it I guess:) Just curious, especially when it comes to highlighting black/shade white.

    ReplyDelete
  11. White and Black aren't colors, as they have no hue. They're simply values. If you want to, you can think of them as the top and bottom of the 3D hue/sat "top" shape that I showed in this article. With every shade of gray between them.

    ReplyDelete
  12. Does it make sense highlighting for instance black with a dark blue? And could you say that any hue goes with a pure value?

    You've made me use HSV instead of RGB when doing the simple things I do with graphical software:)

    ReplyDelete
  13. @Flekkzo

    No, you should almost never use a pure white, black, or gray. It kills all sense of color in your work. Add a bit of blue to the black before you start highlighting it with a lighter shade of blue.

    ReplyDelete
  14. Oh, and beware. Most graphics apps get the math wrong and equate maximum value with maximum saturation. The math for it is simpler that way, but it's not realistic at all.

    Red, for instance, is almost pure 50% gray when it's saturation is removed. But a lot of graphics apps (like photoshop) will desaturate it to a pure white due to this error.

    ReplyDelete
  15. I've got some Legion of the Damned on my table so a blue/black will be coming up, as well as the blue-grey Space Wolves. But what would a good way go do white be? I have some yellow and white combos coming up (IFs first company, just posted a test model only base coated on my blog) and the whites are a bit problematic but I don't want to go for a bone color either.

    ReplyDelete

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