When applying colours to layouts, I noticed that I loose my colour pallette when working with the file on another machine. How do I transfer the colour prefs in the colour picker? I don't see an obvious preferences file to transfer. Thanks in advance.

I don;t know of a way to transfer the preferences across, but can suggest a way to make recreating them faster.

Make a layout in your file with small rectanges of each of your custom colours.

Here is a thread discussing some techniques

Technique