Still haven't figured out why the colors are so bland and I encountered another obstacle: glOrtho that was supposed to enable me emulation of 2D in 3D apparently doesn't work the same way the PC version does. Will have to ask my DS engine programmer friend why is that and how to remedy it.
Tomorrow I plan to work on per-pixel bitmaps and 2D on top, 3D on bottom mode running at the same time. Unless I'll find something cooler to tinker with ;).