try make color spectrum constant lumosity. So try find colors in color spec when go colors/desaturate/luminosity, become 50% value shade gray.

23 and 203 hue have 50% how I find other 358 colors with 50% value when desat?

I do know that you can make an rgb "rainbow" using the following color numbers and when they are desaturated using the lightness setting they all come out the same shade of gray.

Perhaps it could be a starting point for your project. How you would get the rest of the colors I don't know.

ff0000 - red
ffff00 - yellow
00ff00 - green
00ffff - cyan
0000ff - blue
ff00ff - magenta



You may want to take a look here to see if there's something useful you can use.