Color settings for the background seem to come from here:
https://github.com/Cpasjuste/CtrBoo...27f70da8f7ab62/source/hb_menu/gfx.c#L399-L401
line 400 is a gradient so there's two hex RGB values, line 401 only has one RGB hex value. Just edit to 00 for black, or something else using an rgb hex color picker.
You can hex edit the top screen colors so far, still working on bottom screen offsets...
boot.3dsx
offset block 5E5A4-5E5A6 should read: "4A 00 31" replace with starting gradient in rgb hex
offset block 5E5A8-5E5AA should read: "6F 01 49" replace with ending gradient in rgb hex
For example: "00 00 66" "00 00 FF" will give a nice blue to black gradient
Edit: No luck still on the bottom screen, it must be done with a different color or call than what I am expecting or maybe it's being filled with junk? FF 00 FF? Standard transparent pink?
Guess I'll work on trying to get Cmake doing something other than crapping out errors lulz