The "color gamut" display, as you call it, is a GPU test pattern, created by start.elf (or start4.elf, or one of the other start*.elf files, depending on what is booting). That 3rd stage bootloader is run by the GPU which configures other hardware (like the ARM cores and RAM split).
The "color gamut" display, as you call it, is a GPU test pattern, created by start.elf (or start4.elf, or one of the other start*.elf files, depending on what is booting). That 3rd stage bootloader is run by the GPU which configures other hardware (like the ARM cores and RAM split).
https://forums.raspberrypi.com/viewtopic.php?t=336516