: How do I convert a red color scheme to a green one without making it look "brighter" The current color scheme for my desktop uses a red palette. I would like to change it into something

@Gloria351

Your observation is correct. The lightness (the human perception of brightness) of green is larger than the lightness of red.

In your example, when you shift the sRGB value 214,73,55 to 55,214,73 (i.e. you rotate the hue from 7° to 127°), the brightness remains constant at 84 % but the lightness is increased. The original sRGB value 214,73,55 corresponds to a lightness of 52; the new sRGB value 55,214,73 corresponds to a lightness of 76.



You may want to consider using the CIE L*a*b* colour model (Lab), which is based on the human perception of colour, in order to correct the lightness of the new colour.

Using the Lab model, you may directly reduce the lightness of the new colour to 52, which yields the sRGB value 0,147,0. However, this also increases the saturation of the colour.



Alternatively, you may reduce the brightness of the new colour until a lightness of 52 is obtained, which yields the sRGB value 37,143,49. This ensures that hue and saturation of the colour are preserved.

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@Becky351

Basically, you want to use a different model.

Photoshop reports your red RGB(214,73,55) as HSB(7,74,84) and Lab(52,55,42). Scott's comment is probably referencing the "Hue axis" of the HSB color picker.

Lab is supposed to model human perception. There are multiple versions, but for the photoshop color picker, ranges are L=0-100; a & b are -128-127 inclusive. The "a axis" models -green to +magenta. The "b axis" models -blue to +yellow. The "L axis" models lightness.

If you change the sign on the "a" component of Lab to Lab(52,-55,42) you get a green that is pretty close in tone to your red when using the Squint Test.

Wikipedia has a breakdown of the conversions (and footnote to the source docs) if you want to roll your own function.

I think you will probably find an algorithm for coordinated color without human approval very difficult.

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