Hacker News Reader

Comment by gilleain | Hacker News Reader

This all seems like sound(er) advice.

On color : I recently realised (or read somewhere) about the simplest color wheel- if you divide a circle into 6 segments and paint the primaries : {R, Y, B} in non-neighbouring segments, then the ones in between are the secondaries: {R+Y=O, R+B=P, Y+B=G}. Then if you combine primaries and the 'opposite' secondary, you get brown/grey like colors.

Also, I get quite good combinations (palettes) by using a mixture of the same colors, like a red and a green and then a mix of the two to make a grey.

I've thinking about using https://github.com/scrtwpns/pigment-mixing to go from a desired RGB output to the {RGB1, RGB2, percentage) inputs somehow. Would have to be quite rough estimate though, as mixing real paints in exact proportions seems hard.

View on HN

If you want to get things right, I suggest looking at Peter Donahue's Colordisk. He has several great explainers up on Tiktok (sic.), and he has several variants of his Colordisk freely available (his URL shortening, not mine):

https://bit.ly/3gczeBz

I never realised the colour wheel can be navigated using the ab coordinates from Lab space! That makes so much sense.

I've had trouble remembering what the ab coordinates mean, but if I just imagine them on the colour wheel it's obvious that a goes from torquoise-ish to its complement magenta and b goes orthogonal to that, from purple-blue to its complement yellow.

Thanks for linking!

Thanks, that looks very helpful. I have a 'Pocket color wheel' that works ok, but I see that link has a more sophisticated division of color space. Nice!

Is it Red/Yellow/Blue? I believe we were lied to in elementary school — Magenta/Yellow/Cyan are the real pigment primaries.

I always wondered why when we mixed blue and yellow it made for a really muddy green.

RGB are the primary colors used in additive color mixing, CMYK are used as the primary colors for subtractive color mixing which is used in offset printing and similar processes.

In reality, artists often use different base colors anyway. One way to do it is to have 2 versions of the base colors, one warm, one cold. The reason is that for example a greenish blue like Cyan would make it harder to mix vivid violets (by adding a red on the other direction of the color wheel). So you use a greenish blue (Cyan) and a redish blue (e.g. Aquamarine), a blueish red (e.g. Magenta) and a yellow-ish red, and so on.

> primaries and the 'opposite' secondary

The fancy color theory word for this relationship is "complementary".

> a red and a green and then a mix of the two to make a grey.

If you need a black (though you seldom do) it's a good trick to mix one from the colors you're already using.

Reply on news.ycombinator.com