Replace your Flash.exe and timeline.dll with the modded versions. Run as admin.
Painful. Avoid using Flash CS6 on modern Macs altogether. adobe flash cs6 dark mode
Flash CS6 was the last version before Adobe moved to the Creative Cloud subscription model. In subsequent versions like Flash CC (now Adobe Animate), a dark UI became the default. In CS6, the interface is hard-coded with a light gray aesthetic. There is no internal setting in the "Preferences" menu to flip the entire workspace to a dark theme. Partial Customization: The Stage and Timeline Replace your Flash
In 2012, dark modes were a niche hobbyist request. Adobe prioritized features like "Sprite Sheet Export" and "Code Snippets" over UI color schemes. Consequently, the interface colors are hard-coded into the application’s core DLLs and EXEs. Avoid using Flash CS6 on modern Macs altogether
If you can afford the $20/month subscription, stop torturing yourself with CS6 dark mode hacks. The time you save on eye strain and crashes is worth the price.
Since there is no "Dark" checkbox, users often use these workspace tweaks to create a high-contrast, eye-friendly environment: