You may like to use Mesh Wizard to tune your mesh.
[ame="http://www.orbithangar.com/searchid.php?ID=2740"]Mesh Wizard 1.9d[/ame]
You also may want to read the manual, since MSH format is explained there.
For one material you have 4 lines (going to describe them for MSH format):
Diffuse: Base material color that is used for coloring texture (you may think as "skin color")
Ambient: Color of reflected light from surface when close to planet.
Specularity: Shining factor
Emissive: How lighted material is at night (artificial light, usually inside vessel cockpit)
Each line has 4 numbers. For example:
0.008 0.651 1.000 1.000
The first 3 numbers are RGB values, and the last one is opacity.
Specularity uses 5 numbers, and the 5th number is specularity power. See Mesh Wizard manual to see what it is.
All values range from 0 to 1.
As you probably may know RGB stands for red, green, blue, which are the 3 basic colors to create all colors on a TV screen. Such RGB values indicate how much of each color it will have. Mesh Wizard allows you to preview colors.
Opacity has different meanings, depending on the line.
It also has different meaning, depending on 3D file format.
Transparency is given by diffuse opacity value in MSH format, where 0 is transparent/invisible and 1 is opaque.
All available convertors use to convert color data differently, in some cases accurately or in some cases data is lost in the conversion. Mesh Wizard has some details on it.
In the case of MeshMaker it converts UV texture coordinates inverted, so it gives a weird appearance if you used textures.