We are not clients yet. But I have been showing the suite to my team. Some of they are worried about the complexity of add custom themes. There is any plan to expose theme colors in the future, for example using css variables? Or for example could be the sass/scss code available for each release?
There are no custom themes fro the dhtmlxSuite, but you may refer to the following pasge with some custom templates:
Also you aret able to apply your own custom css to change the look af any dhtmlxSuite compoent.