Before starting separating your design, choose the separation quality type:
The fastest and easiest way to create a color filter is double clicking with on a color that you wish in the original image and the separation channels will be done instantly. See below separations done with this method and the results on the separations screen on the right preview. The channel number will be created as S-1, S-2 etc.
Another way to do it is to create a new separation from channels options. Create a new channel from
Back to the original image, click on a color you wish (with the cmd button pressed), and the separation for that color will be created on the separation screen. Searching for surrounding colors in the separation channel you can select it from color picker. Or using Shift + ⌘ Cmd + click (windows: Shift + Ctrl + Alt + click) on the desired color to set center color. It will select the new color in the image and change the new channel in the separation screen.
Lowering the color separation tolerance the color selection will be reduce in the lower percentage in the separation.
Working with 'Plain ink' it converts separation in 100% grayscale and creates flat separation, ideally for spot colors and background designs.
Grouping the separation joins color separations in one group to be independent in color mix with other channels, which allows different color combination after separations. Here is the example of grouping channel when having 6 groups:
Working with alpha channel mask in your image you can exclude the color separation in the masked area. The white of the alpha channel is detected as mask.
In the plug-in you can exclude the separation from the option 'Mask' where you can select the alpha channel mask.
Once the mask is applied, the separated color will be removed from the separation.
Using the inverted option, the mask selection will be inverted and applied to selected color.
Select a channel, double click on color patch and it will open the color picker to change the channel color.
From separation preview window, the button with an arrow next to the zoom, you can choose different preview modes. On each preview window, displays yet more preview options.