Complimentary colors in photoshop

Forum|Forum|3 years ago
June 20, 2022
3 replies
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If you look at the color wheel in photoshop it is the RGB color wheel if you look across from Red you will see cyan. If you look at the color wheel in adobe cc, although it doesn't say it is actually the RYB color wheel where across from Red is Green. The question is which color wheel should be used and when. I have my opinions but not sure if they are correct which is based on the fact that RYB is a subtractive color system where RGB is an additive system. My guess is that adobe CC uses the RYB color wheel to produce pallettes because the assumption is that the final product will be printed and thus the subtractive method makes sense and in the subtractive system Red and green are compliments and have the largest impact. I believe in the subtractive system adding compliments tend towards greys/black. However my question relates to blending colors in photoshop for operations such as removing color casts, in this case we are mixing colors purely in an additive system and it seems to me that we should use complements from the rgb model (hence use cyan to counter red). 100% green 100% blue and 0% red result in cyan, In this system blending colors moves towards whiate. It has been pointed out ins several sources to get the compliment of a color either subtract or add 180 to the hue in the hue saturation brightness model to get the compliment (hence cyan is across from red). Does this make sense or is there a better explanation. Also is there a better place for this topic

Cross-app workflows

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D Fosse

Community Expert

This is a result of how color spaces are specified. 255-0-0 is the complementary to 0-255-255 - in whatever color space those numbers apply. That's a 180 degree shift on the Hue slider.

In Lab, which is what all color management refers to, swapping positive and negative values in the a and b channels will give you "opposite" or "complementary" hues.

Those two things operate on different precision levels. A color wheel is a generic model of maximum saturation hues. Color spaces are stringently defined and specified from all possible values.

TheDigitalDog

Inspiring

You should provide a screen capture of whatever color wheel product you're referring to but Photoshop is doing this correctly; the 'opposite' of red is cyan.

Author “Color Management for Photographers" & "Photoshop CC Color Management/pluralsight"

B

billb4681569Author

Participant

May not have been clear in my past question: Based on my conversation above, photoshop is using the RGB model (additive color model), Adobe Color(Color wheel, a color palette generator | Adobe Color) I believe was created to replace the Kuler color wheel in older versions of photoshop. It can be used to make color swatches based on different color harmony rules such as complimenty colors but it appears to use the RYB model vs RGB. I am just trying to confirm that if you are going to be printing something and using complimentry, anologus or other color harmony rules the correct thing to use is the RYB model (adobe color swatches) since it is subtractive and physical media usually relies on subtractive systems such as RYB and CYM, but if you are going to be mixing colors digitally the RGB (in photoshop) model should be used since digital media is based on the additive RGB model. Hence if I am producing a print the maximum color contrast for a red subject would be a green background (from adobe color), but if I am correcting color cast of a red in a subject in photoshop I should use cyan as the compliment.as indicated in photoshop. Both the adobe Color Web site and photoshop are adobe products and from what I can tell are both meant to be used with photoshop I am just trying to understand when one Color system (RGB vs RYB) should be used vs the other.

TheDigitalDog

Inspiring

If you're printing from RGB, all that you need to worry about is an appropriate ICC output profile which may produce output RGB or output CMYK, and if RGB, the print driver will handle conversions to whatever it needs (perhaps CcMmYKO etc).

There are very, very few true RGB printers (Lightjet, Lambda using lasers or light values, Film Recorders etc). Just stick with Photoshop's correct implementation which again, shows cyan is the 'opposite' of red.

Histograms too.

Author “Color Management for Photographers" & "Photoshop CC Color Management/pluralsight"