Friday, September 11, 2015

Solving the problem that is yellow

I often see conversations on ARC and other forums about painting yellow. It seems to be one of the more challenging colors to work with. I've never had to paint a large area of yellow myself, but with a few models in the stash that will eventually call for yellow (T-6/SNJ, T-28, Blenheim), I've been anxious to see if it’s as hard a color to apply as people seem to imply. Of course I'd use my paint of choice, Tamiya.

Before accepting the challenge, it might be helpful to briefly review basic color theory.

Three attributes define all colors:
  • Hue – the simple name for a color, such as yellow, red, blue.
  • Lightness – a color’s value in terms of whether it can be described between two poles of light and dark (or black and white).
  • Saturation – a color’s colorfulness, that is, whether it’s intense or dull or somewhere in between.
Let’s talk about hue. I’ll share a simple thought: Yellow, even a specific pigment such as FS 33538, is basically…yellow! As I suggested in this post a year ago, don’t obsess over finding or using a “correct” yellow for your model. Be content with a color that any reasonable person would identify as yellow.

That leaves us with lightness and saturation. There are many factors that affect the specific yellow that you see on a 1:1 scale airframe. There’s the sun's illumination and its light being filtered through clouds, real-world weathering, variations in the manufacture of the color used on the actual aircraft, the correct mixing and application of the paint in the factory or field, etc. Likewise, there are many factors that affect the specific yellow that you see on a scale model. The light in the room, scale effect, the paint you used, your ability (and a viewer’s ability) to correctly see color, and the memory that you (and a viewer) have of what they think the correct color should be.

Those factors affect the lightness and saturation of the colors that we see. Accepting these variables and knowing that you cannot control all of them makes it easier to be comfortable applying a color to your model that looks like yellow.

The challenge with painting yellow is the opacity of most paints. They generally don’t cover well, so you have to use a thick application or many thin applications. The former is problematic because thick paints don’t flow efficiently through an airbrush, and the latter is problematic because many layers of paint tends to obscure detail.

With all this color theory in mind, I set out on an experiment by selecting a suitable model, Sword’s 1/72 Northrop N-9MA Flying Wing. Pretty crude kit, but the point of the project was learning how to paint yellow not superdetailing. Nevertheless, I added a few things here and there, particularly splitter plates inside the leading edge air intakes, and I had to scratchbuild a new front landing gear when the kit piece broke.

Earlier this week I arrived at the painting stage. First I applied a suitable blue to the underside of the aircraft, custom mixed by eye. Simple.

Then I thought through an approach to yellow that would address the challenges I described earlier. Most modelers suggesting a white undercoat prior to the yellow. I’m not one to apply bright, true colors to my models, so I decided to try something different. I wanted to try a tan color with a marked yellow hue. I decided on Tamiya XF-59 Desert Yellow mixed 50:50 with XF-3 Yellow, the paint I would use for the main color. I theorized that tan would provide a deep primer color that would not subsequently require copious amounts of yellow. And I was right; the color was perfect for a reasonable application of yellow.

In thinking about the final yellow, I’d read that opacity was problematic, so I decided to follow this “tan theme” and mix a bit of the same Desert Yellow into the main yellow color, which I theorized would increase its opacity. I used Tamiya XF-3 Yellow, XF-59 Desert Yellow, and XF-2 White in a 4:1:1 ratio respectively, the white used to bring down the color a bit for scale effect. Again, the result was a satisfactory color that, I think, is slightly lower in saturation than it would’ve been had had I used the pure yellow out of the bottle.

I’m very happy with the result, especially after some subtle post-shading, though to be self-critical I don't think I used the right color to tint the yellow. A pin wash and weathering will ultimately follow, which I expect will alter the finish a bit.

As you approach painting challenges, I encourage you to think outside of conventional wisdom. Follow your intuition. Try something new. Make your own path. You might be surprised what you learn along the way.


  1. Great post, as always. I'm planning to build an Fw190 as captured by the RAF, and as it has a yellow belly, err... undersides, I will definitely try this approach!

  2. I adhere to the white undercoat theory myself. Obviously other methods will work fine, but I like things simple. Same goes for red. I have terrible AMS, and as time goes by I find myself less worried about techniques and details and more focussed on just finishing the damn model. Clearly my rivet counting days are beginning to recede into the past. : )

    1. To completely get off topic, I've been told by car modellers that your better off using a light beige/tan color as an undercoat for Red. It looks a bit dull over a flat white base.

  3. This is what a really love about the internet, knowledge sharing. A great post as always.