We are using Aegir, we would like to use one core theme for all of our websites which handles common theming. But for specific theming for each site, we would like to handle inside of their custom themes.
Basically this will enable us that we can change common theming in just one theme used by all, instead of making the same changes in every theme of respective site.
One challenge by creating the custom theme in one of websites it will overwrite code from common core theme, but both themes should be present in the same time. Is there any kind of solution for something like this?