Since Adobe never built an official dark theme for CS6, you have to modify the program's internal files and use a system-wide workaround. Proceed at your own risk (always back up original files).
Adobe CS6 on Mac uses internal .nib files. This requires replacing the light theme with a community-made dark version. adobe flash cs6 dark mode
Moving to a darker workspace isn't just about style. It helps with: Reduced Eye Strain: Especially in dim environments. Since Adobe never built an official dark theme