RYB Color Wheel

[tight flint]

Hello, i've a rgb code - e.g. 255,0,0 (red)

I now need the degree of that in the wheel - see image

So:

• Red -> 0 (°)
• Green -> 180 (°)
• Orange -> 90 (°)
  ... any ideas how to do that?

[sweet imp]

<@&987246399047479336> please have a look, thanks.

Here is an AI assisted attempt to answer your question 🤖. Maybe it helps! In any case, a human is on the way 👍. To continue talking to the AI, you can use </chatgpt:1108714622413963314>.

To determine the degree of a color on the RYB color wheel, you can use the following steps:

1. Convert the RGB values to RYB values. The conversion from RGB to RYB is not straightforward, as it involves some complex calculations. However, there are online tools and libraries available that can help you with this conversion.

2. Once you have the RYB values, you can map them to degrees on the color wheel. In the RYB color wheel, red is typically represented at 0 degrees, green at 180 degrees, and orange at 90 degrees.

3. Calculate the angle between your color and each of these reference colors (red, green, and orange) on the color wheel. You can use trigonometry functions such as atan2 or arctan to calculate these angles.

4. Determine which reference color your color is closest to in terms of angle and assign the corresponding degree value.

Note that this method assumes a standard RYB color wheel where red is at 0 degrees, green is at 180 degrees, and orange is at 90 degrees. If you are using a different color wheel with different reference points, you will need to adjust accordingly.

[white willow]

pretty much what the bot said

u just need to convert color model. Wikipedia has the algorithm for u, it's straightforward

[tight flint]

https://en.wikipedia.org/wiki/RYB_color_model#:~:text=RYB (an%20abbreviation%20of%20red,pigments%20are%20considered%20primary%20colors.

I cant find there any algo

[white willow]

https://en.m.wikipedia.org/wiki/HSL_and_HSV

HSV is what u want

the hue value is ur degrees

so u convert RGB to HSV and grab the H value

depending on the algo, its likely 0-255. so u lerp that to 0-360 and that's it

here is a useful link. it's the other way around though:
https://stackoverflow.com/a/46929712

[tight flint]

But for some reason it doesnt calulate some right

[tight flint]

any ideas what I got wrong there?

[tight flint]

public static void main(String[] args) {
        float hue = Color.RGBtoHSB(0, 170, 0, new float[3])[0] * 360;
        System.out.println("Hue: " + hue);
    }

=> 120

120 ist not green, its yellow

[grizzled steeple]

0, 170, 0 is not green though

[tight flint]

it is

[grizzled steeple]

Yeah it looks like green

But 180 degree is 0 255 0

[tight flint]

But then I somehow need to get 160 or sth

Not 120

thats yellow

[grizzled steeple]

Yeah ik, your calculation probably wrong

[tight flint]

can you then say me where the error is?

[grizzled steeple]

Even 0 255 0 is H=120

Just checked with a website

Then it might not be what you want

Or there is an offset

Also I think you can’t just compare one specific degree like 180 with a specific color because multiple colors have the same hue

There is a reason why hsb stores three values

[tight flint]

how can I calculate the degree then

[white willow]

the H value, as explained earlier, is 0-255

not degree

to get degree, u have to lerp it to 0-360

[grizzled steeple]

check his calculation

float hue = Color.RGBtoHSB(0, 170, 0, new float[3])[0] * 360;

I think its 0 - 1.0

[white willow]

so h / 255.0 * 360

fair

it depends on the algo used

[grizzled steeple]

and I checked with a website

same result

[white willow]

so u used HSV, HSL or HSB?

what input color did u try and what was the HSV value u got?

ah. now i see what u want

well, as. the bot originally explained. u have to convert to RYB first

this gives u a vector in this space

after u have the vector, u have to compute the rotation angle it represents on that plane

[tight flint]

I dont really understand, sorry 😭

[grizzled steeple]

https://math.stackexchange.com/questions/305395/ryb-and-rgb-color-space-conversion

this might be helpful