The color palette inkwell colors are represented by hardcoded NSColor values in one of the inpenetrable *.IWA files within the template bundle. Apple may have software that scans the .jpg files and generates this palette from predominant colors in the image. There is no Pages user means to customize these inkwell colors, but you can borrow them for your own custom color palette.
Open a Pages template with the donor colors that you want to copy. Open a recipient blank document in another window/tab.
Open the Color Chooser in the Blank document and switch to the Color Palettes panel.
- Click the gear icon and choose New
- Click the gear icon and choose Rename
Give your palette a meaningful name
- In the source document, click on the text color inkwell, and select the first color that you want to copy. This color will now appear in the inkwell.
- Press the command key and click/drag the color in the Inkwell across into the open color palette and drop it.
- Switch to the preceding RGB sliders item, select RGB Sliders, and copy the hex value.
- Switch back to the color palette, click on the new color entry, and paste the hex color value next to it for documentation.
- Repeat item 3 until you have the desired color palette constructed. It is autosaved as you are copying colors into it and it will be stored in <username>/Library/Colors as palette_name.clr.
- You now have a palette that you can use for future documents, and it is not restricted to the blank document that hosted this exercise.
Using Yellowbox's Term Paper template example as the donor document, I made a new TermPaper Colors.clr palette reflecting the first column of colors from the Term Paper template's inkwell: