Magic Is The Perfect Description – Paper for the iPad and the Colour Mixer

I have low expectations of Fast Company articles. Which is fair enough, really, as the content is usually targeted at the layman: much like when I read Popular Science and get some superficial knowledge of something complex (say fusion reactors), but in reality have gained virtually no real understanding.

It is knowledge pablum.

This article on a new feature of Paper (a highly lauded iPad application from a company named FiftyThree) meets my expectations for a Fast Company piece.

As a backgrounder, Paper has done well despite the fact that it offered only nine pre-selected colors, and despite the sparsity of drawing tools, each demanding an in-app purchase.

It had, and still largely has, extremely limited on-paper color dynamics, lagging behind drawing programs of the 1980s (much less incredibly rich, color-innovative apps like Corel’s Paint).

They had a nice interface and good brush stroke dynamics, but from a color theory perspective they were absolutely bottom of the barrel: It would have been hard for them to do worse.

For them to add a rudimentary color mixer is clearly a good improvement.

The claims behind it, though, are perhaps a bit exaggerated.

From the author of the article-

Open the color picker, and choose a color midway between yellow and blue. Any kindergartner will tell you the result should be green–but no matter what machine or software you’re using, you’ll get a drab gray.

Every paint program will give you a hue gradient where green lies between yellow and blue, exactly as expected. I would show some screenshots, but given that even Paint included in Windows does this, there is no point. The hue gradient is important because it is the foundation of the “magic” behind Paper, allusions to complex algorithms notwithstanding.

From one of the people behind the app-

“In computing, most colors are expressed as RGB triplets. “We learned in elementary school that yellow and blue when mixed turn green,” says Petschnigg. “However when you plug in the values to this equation, you get a different result: Gray! Mathematically speaking, yellow (1,1,0) and blue (0,0,1), blend to the triplet (0.5, 0.5, 0.5) which is gray. This is because RGB only describes a point in a color spectrum, not how colors would behave when they blend.”

Hopefully they learned, as I did, that are two separate color systems – additive and subtractive. Computers generally use RGB because it is an additive system (it is adding new color frequencies via the RGB panel of your monitor, versus taking colors away ala light gels or paint additives).

Regardless, we’ve always had alternative color schemes. HSL, for instance (which you can easily convert to and from RGB, and is natively supported in CSS 3.0). While it is mentioned in passing in the article, its importance is perhaps underplayed.

“In searching for a good blending algorithm, we initially tried interpolating across various color-spaces: RGB, HSV and HSL, then CieLAB and CieLUV. The results were disappointing,” says Chen. “We know red and yellow should yield orange, or that red and blue should make purple–but there isn’t any way to arrive at these colors no matter what color-space you use. There’s an engineering axiom: do the simplest thing that could possibly work. Well, we had now tried the easiest possible approaches and they didn’t feel even remotely right.”

Orange lies midway between red and yellow in the HSV and HSL color schemes. Purple lies midway between red and blue. Which they surely know because it’s what they use, whether directly, or, if they wasted a year reinventing the wheel, indirectly.

When you use the color mixer in Paper it takes your starting color and does a close to linear transition through the hues in the HSV color space, from source to end color. It does the same with the value. It suppresses saturation midway through the “blend” (aka transition through the HSV world) — hitting minimal saturation at the halfway point — bringing it back up once you reach the target color. With enough tests and the motivation, you could easily extract the exact algorithm used.

This is why you almost universally end up with a dingy dirty washtub color midway through, as it’s invariably a desaturated mask of the travels across the HSV space.

I know this because I wasted the time doing a variety of tests with the app (with a wide range of from and to colors of varying hues, saturation and values), taking screenshots along the way and then extracting the HSV & HSL map. The pattern is obvious. The limited deviations from the direct transition are of questionable value.

I think what bothered me about the article and the various quotes is the unfounded “everyone else is an idiot” attitude. By the makers of a product who gave you nine curated colors, no less, and now offer rudimentary HSV mixing. It is another example of the “strength through weakness” pivot that has become so popular (e.g. that vendors who have incredibly limited offerings in an area are somehow more credible when they resolve their own failings).

In their favour, I suppose, they’re just trying to sell an in-app purchase. It’s just weird that such a fluff piece saw so much attention in the tech space.


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