Color Palette in 2k3

[TeaBag]

The whole limited color selection thing in rpg maker 2k3 has always annoyed me, and I've always wondered if I'm using as many colors as possible.  I was annoyed to find that the rtp tilesets actually has more colors than my own, which I save as 256 color bitmap.  what?  Can someone inform me as to how I can save my files w/ the most colors possible.  Does it have something to do w/ that retarded color table?

for example:
the rtp grass, so perty


when saved in the file type I use...

two measly shades of green!

why does they gots more colors when rpg maker can aparently only read 256 bitmaps?  AUUGH!