It's kind of self-explanatory with these pictures.






Upon, looking at Krita, there are still sometimes when I have to resort to Paint.Net for this tool, and the main thing I use this tool is for extraction of color information. Select by color range isn't enough as there's still no way to select by colors between the primary colors and the secondary colors. Furthermore, this is another way to fine-tune colors. There's some few applications here. Also, I believe this tool might reduce some amount of time to achieve certain effects. Color Balance is the closest thing I can find to this, but you don't have as much control over colored areas. Thanks for reading, though.