Hi @GaoKT
The way to share your themes is to export all their parts into a file, make the file available to the person you want to share it with, and they can then import the file to make use of your theme. The steps to do this are as follows.
Press the Windows button and type (without quotes) "Settings"; then press Enter. Windows displays the Settings window
Click the Personalization group (near the center). Windows displays the Personalization section of the Settings window.
At the left side of the window, click on Themes. Windows displays the Themes option of the Personalization section.
Right-click the theme you want to export. Windows displays a Context menu.
Select the "Save theme for sharing" option. Windows prompts you for where you want the file saved.
Use the controls in the dialog box to select a location for the file and specify a filename. (You can put it on a shared drive that your colleague can read, or just put it on the desktop so that you can easily mail it to him/her.) The file will have a ".deskthemepack" extension.
Once your colleague has the file for the theme, they simply double-click the file to import it into their system. (They must be running a Windows 10 system, as well.) For them to apply this theme, they go to the Themes tab and select it.
I do hope this answers your question.
-----------
--If the reply is helpful, please Upvote and Accept as answer--