Hi singhanart-nakpongphun,
We investigated about the issue and found the solution for changing category color for the respective translated language. What you need to do is first go to the Dashboard and choose the specific language from the top bar of the Dashboard. Then go to ‘Customizer’ and choose the same language that you have chosen in Dashboard on the live preview of customizer screen. For Example if you have choose English language in Dashboard then you have to choose the same english language on the Customizer live Preview so that you can be able to set the category color and repeat the same process to change category color for other languages.
Thanks