Solved
AN4861, rev 4, page 22, '18-bit RGB888' should be '18-bit RGB666'
AN4861, Application note, LCD-TFT display controller (LTDC) on STM32 MCUs

AN4861, Application note, LCD-TFT display controller (LTDC) on STM32 MCUs

An internal ticket number 173079 is submitted in order to update the AN4861 on this point.
(PS: Ticket number 173079 is an internal tracking number and is not accessible or usable by customers).
Thanks again for reporting this.
Best Regards.
STTwo-32
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