Finding Colors that Desaturate to the same shade of grey

[mokus]

I can't find anything on this, so it might be a bit weird of a question.

Is there an easy way to know which colors will desaturate to the same shade of gray?

Is there a rule of which values of a color will calculate into the values of the shade of gray?
Are there already pallets of these colors that go to the same gray?
Assuming there are such pallets of colors, are they different if instead of desaturating you convert the image to gray scale?

I know this is unique. I hope someone has an answer for this. Thanks!

 

[thebestcpu]

Hi Mokus

It would really help to know what you are trying to achieve in your project or is this just an academic question.

The answer is yes and no (how is that for an answer)

Turns out it depends on the color space your are in and the approach or tool you are using to desaturate (not consistent in PS).

For example, as you desaturate using the Hue/Sat adjustment Layer in sRGB, the Luminosity of the image is not held constant. However, if you desaturate an image by using an all black Layer over the image set to Saturation Blend it will.

In Lab mode the Hue/Sat adjustment Layer will work properly as well.

I would be more than glad to direct you in the right direction it you could add more specifics one what you are trying to achieve. Not just a simple answer.

John Wheeler

 

[mokus]

Thanks for the detailed reply. I have a project I would like to do. The key is using colors that desaturate to the same gray. However I will not be doing the desaturation, my project partner is. And as you state, that is the big variable, how the desaturation is done. I have been asking my project partner but haven't gotten an answer back. I will find out and post that update here.