If your colleagues have also customized some of their own categories then you can selectively send specific ones to them.
Firstly on your own PC:
- Create a new map (you only need a core, no other branches)
- Assign every category from your custom category set to the branch
- Save the map file somewhere accessible (Documents, Desktop etc) and call it something like Cat Transfer
- Attach the map file to an email message and send it to your colleagues
Secondly, on your colleagues' PCs:
- Open the map file you distributed
- Right click over the branch with the categories assigned and select "Categories..." from the context menu
- Scroll down the category list until you see the custom category group(s)
- Right click over each custom group name (not each individual category) and select "Add all items to My Categories"
- Click "OK"
Once you've done that your colleagues will be able to add your customized categories to their category gallery via the More Categories menu at the bottom on their gallery.