Hi
You are right.
This states in UM.
TFT panels only support one or more of the following color modes:
• 1 bpp, palettized, 2 colors selected from available colors.
• 2 bpp, palettized, 4 colors selected from available colors.
• 4 bpp, palettized, 16 colors selected from available colors.
• 8 bpp, palettized, 256 colors selected from available colors.
• 12 bpp, direct 4:4:4 RGB.
• 16 bpp, direct 5:5:5 RGB, with 1 bpp not normally used. This pixel is still output, and
can be used as a brightness bit to connect to the Least Significant Bit (LSB) of RGB
components of a 6:6:6 TFT panel.
• 16 bpp, direct 5:6:5 RGB.
• 24 bpp, direct 8:8:8 RGB, providing over 16 million colors.
Each 16-bit palette entry is composed of 5 bpp (RGB), plus a common intensity bit. This provides better memory utilization and performance compared with a full 6 bpp structure.
The total number of colors supported can be doubled from 32K to 64K if the intensity bit is used and applied to all three color components simultaneously.
Alternatively, the 16 signals can be used to drive a 5:6:5 panel with the extra bit only
applied to the green channel.
Have a nice day,
Jun Zhang