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I need to "rotate" colors depending on a certain dependency, how do I calculate this?

I'm using no program, just working with a bitmap in C#

For example:

Every pixel, which is R:193,G:0,B:0 has to become R:0,G60,B:90

Now every other color needs to be switched in relation.

193/0/0 has a neighbor pixel with 205/48/48, what I'm searching is the relative neighbor pixel of 0/60/90

Is there a way to calculate this, without getting values above 255 and beneath 0?

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    I think the key will be finding the adjustment to hue, saturation, and brightness /value/lightness that turns your dark red into your dark blue, then applying that to everything. How to do this will depend on what software etc is being used. – user56reinstatemonica8 May 15 '14 at 14:36
  • There really is no such thing as color rotation, its just a trick of the color system. You could equally well try HSV as HSL which are subtly different and yield different results. There is no guarantee they yield satisfying results. – joojaa May 15 '14 at 14:58
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This is a complete stab in the dark, but here is what I would try: The HSL values are 200/100/35 and 0/100/76, so rotate the value of each H value by 200° and add 41% to each L value (clipped at 100).

More information from thebodzio's comment:

I think what you really have in mind is “mapping”. In that regard it's like any other mapping between two vector spaces (with some clipping/wrapping; not necessarily bijective process). The problem is, there's infinitely many such mappings. You just have to formulate one that suits you best. @JohnB's proposition seems to be the most reasonable in that regard, however it requires conversion from RGB (sRGB?) to HSL and back. Algorithms are easy enough to find.

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  • why not rotate -160 degrees which is closer? – joojaa Jul 14 '14 at 17:02

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