I have noticed that Channel Mixture under color tab is not showing in my Photolab Elite version 6.
I notice that when Youtubers instruction showed that.
How can I activate it so it comes up ?
The Channel Mixer tool is part of FilmPack. You’d need a FP license and apply it in PhotoLab.
To add the what @platypus indicated there are also a number of other very useful features in FilmPack 6.2 Elite, including such things as four fine contrast sliders, Creative vignetting, various filters, a creative blur tool, DxO FilmPack Time Machine, and a number of other tools, not to mention around 100 film emulations.