Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/STMicroelectronics/STM32L4S9/LTCD/L1DCCR#0x0
LTDC Layer Default Color Configuration Register
Default Color Blue
Default Color Green
Default Color Red
Default Color Alpha
https://github.com/cmsis-svd/cmsis-svd-data