Great! I hope now you have information that you need:
I look forward to the results. 
This is how i see the channel mixer for artistic color grading
example:
cyan + magenta = blu
original
what if we add cyan and magenta to blu?
add cyan and magenta in blue, add yellow to green
saturation
cinematic , similar to (teal / orange)
Questions:
- Why isn’t it red?
- How do you get it red so that green grass stays green?
Here is the original picture:
[/quote]
Here you have added yellow and red to blu, yellow + red= orange
Thanks Boris hopefully the transition to the DT channel mixer was obvious but your pic makes the point…I just thought the gentleman that is a retired teacher…explained and demonstrated it very well for anyone following the thread…thanks for the exclamation point…
I’m working on it… just work and life gets in the way of opensource contributions 
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Hi all - is there a way to split this thread into one for clarity and one for channel mixer? Great info in here to refer back to but people may not notice the channel mixer info due to the tread title.
I’m for it, but I don’t know how. Maybe we ask @paperdigits for help? 
Yes I can do that. Give me a few minutes.
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There you have it. Hopefully I picked the right topics… for topics that had mixed replies, e.g. some on filmic and some on channel mixer, I left them on the filmic thread. There were not that many.
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Great video and more in the same series….! I hope to see some practical examples on why/how to use the channel mixer……
! Theory is great, but not so interesting if I’m not able to put it into practical use……
So, if your destination is the red channel then the blue slider adds/subtracts red from pixels based on the amount of blue in the pixel and the position of the blue slider. A little hard to grasp from text but easy to understand when watching the video! Thank you……
The destination can be r/g/b or h/s/l, when would you ever want to choose h/s/l as the destination?
Thank you @paperdigits!
Yes even when you know it is still a bit hard to work with at the start…for example adding green slider in the red channel makes it less green not more as it boosts the red overall so it can work in a way backwards at times and their
is basically the simple math behind it…its good to have the color info on the screen to see how it changed the overall pixel RBG values that helps me to keep track…Glad the video way helpful…I think I insulted Boris by including him…was just looping
him in and not suggesting he was lacking the knowledge…happy color mixing…
Mail](https://go.microsoft.com/fwlink/?LinkId=550986) for Windows 10
Hi’ @s7habo
This photo could be one of the problem photos you were asking for. The result of my edit is that the people are relatively ok but the cherry flowers are way to “heavy”. I would like “fluffy clouds of pink”. I hope you see what I am aiming at. Can this be achieved by channel mixer (and other tools)?
DSC_8833.NEF (31.1 MB)
Not so easy, because local contrast is very strong and the shadows are harsh.
But you can improve it a bit with channel mixer. Details later. Need to go now.
DSC_8833_01.NEF.xmp (9,9 KB)
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Starting from a simple base curve + tone curve edit
With the channel mixer is possible to add magenta to red
add cyan to blue
DSC_8833.NEF.xmp (7.7 KB)
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I though I had a reasonable understanding of how it all worked. To make it more accessible for others I decided to start making a nice visual representation based on a simplified RGB+CMY colour wheel. Change some sliders from 100% to 50%, 0% in one or more channels and show the result, accompanied with the RGB values , slider settings and percentages.
I was immediately confronted with an unexpected result: Setting a slider to 0.500 does not represent 50%. I cannot get my head around why this is the case. I’m trying this in GIMP, but I also used this method in darktable and reading it back in GIMP gives the same result.
Are these values not linear?
Ok, here are 2 screenshots to show what I am talking about:
This one shows a normal starting point as can be seen in the top right window and the channel mixer setting:
Here I changed the Red in red channel to 0.500, which I thought to be 50%
As you can see the RGB value is 188,0,0 and the RGB percentage 73,5%
I expected them to be 127,0,0 and 50%. To get to the numbers I expected you need to set the Red in red channel to 0.214.
I’m sure there’s something I do not get/understand but I can’t find a clue. The GIMP docs seem to suggest that 1.000 is 100% and 0.500 50%.
Anybody here to enlighten me on this issue?
The channel mixer in gimp works in linear gamma but the color picker displays the values in srgb gamma encoded.
Red in linear gamma= 1 0 0
After the channel mixer in linear gamma = 0.5 0 0
The color picker in srgb gamma =( 0.5 0 0 )^ 0.45 = 0.75 0 0 => 75 %
I’m not sure if it’s correct but if you check the gamma hack option in advanced colour option it should works
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I think the answer has to be: It depends on the specific situation.
That’s why good tutorials try to deal with the underlying concepts rather than being simple recipes.
Really understanding color has to be a foundation for manipulation of color photographs.
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This can’t be said loud enough! 
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Strange that this gamma hack is not the default in GIMP. If I go on-line and play with RGB based colour sites they all show 50% as: R127,G0,B0. The Converting Colors site gives an elaborate summary.
As a numbers guy I’m going to leave this option checked for the time being…
@age: Thanks!
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@Jade_NL Check this out…this is a really nice demonstration…the previous video to this one is good too but this is a dynmanic view of the wheel… and he is a former teacher so he does a nice job to break it down… https://www.youtube.com/watch?v=zgTLw31PVNs