Well, If your colors you want to add in exceed the limited 256 pallete, then your simply out of luck.. Although you can edit the z- Levels that is used with Dragon very easily..
Open your dragon/scripts/MapTrans.txt Dirt is as follows..
Code:
// (09) dirt big stones dirt small stones
80 09 000 0071 0072 0073 0074 0075 0076 0077 0078
81 09 002 0071 0072 0073 0074 0075 0076 0077 0078
82 09 005 0071 0072 0073 0074 0075 0076 0077 0078
83 09 010 0071 0072 0073 0074 0075 0076 0077 0078
84 09 012 0071 0072 0073 0074 0075 0076 0077 0078
85 09 015 0071 0072 0073 0074 0075 0076 0077 0078
86 09 020 0071 0072 0073 0074 0075 0076 0077 0078
87 09 022 0071 0072 0073 0074 0075 0076 0077 0078
88 09 025 0071 0072 0073 0074 0075 0076 0077 0078
89 09 030 0071 0072 0073 0074 0075 0076 0077 0078
8a 09 032 0071 0072 0073 0074 0075 0076 0077 0078
8b 09 035 0071 0072 0073 0074 0075 0076 0077 0078
8c 09 040 0071 0072 0073 0074 0075 0076 0077 0078
8d 09 042 0071 0072 0073 0074 0075 0076 0077 0078
8e 09 045 0071 0072 0073 0074 0075 0076 0077 0078
First line definition is:
80 = this is the first color used in the Palete.. the lightest brown shade.. 81 is the next darker.. 82, 83, 84, etc.. to the end of the color row..
09 = the group that Dirt is defined as, for dragon to recognize what is attribute with it..
000 = the Z level for the first color on this row ( 80 - 8e ) to set its dirt tile..
here is where you can mod your dirt z levels...
0071 0072 0073 0074 0075 0076 0077 0078 == these are the dirt tiles that Dragon will 'randomly' place when it reads the colors 80 - 8e
hope that helps a bit.