Astah System Safety provides plenty of light/dark themes since version 8.0. You can choose your preferred theme to apply to Astah System Safety from [View] – [Look & Feel] in main menu.
Background of Diagram Editor
Currently, themes do not apply to diagram editor’s background color. If you want to tune it up to fit the dark surface, you can change it from [Tools] – [System Properties] – [Basic] – [Diagram Editor] – [Background color].
There are nearly 70 pre-installed themes you can choose from. Here’re the previews of each one of them. Or you can see the best 8 themes we recommend.
To see all available themes, please pick the category.