GRUB 2 likes its PMG files in RGBA flavour.
-rw-r--r-- 465 Makeconf
-rw-r--r-- 797 Makefile
-rw-r--r-- 322 Makerules
drwxr-xr-x - bootloader
drwxr-xr-x - icons
drwxr-xr-x - objects
drwxr-xr-x - plymouth