William: There are a number of things you can play with. Here are a few ideas.
1). You can add code to lerp with another texture.
2). Alter the pixelshaderconstant like: PixelShaderConstant[0] = {0.60,0.60,0.60,0.50}; x,y,z being RGB. w being transparancy.
3). You could pass info thru diffuse by adding:
float4 vecDiffuse // Add vector to effect ""
PixelShaderConstant[0] = <vecDiffuse>; // Change in Technique Pass
mul r0, t3, c0 // No change in pixelshader fragment
my.Alpha = 60; // Add the amount of trans to your Action
In the material {}; // Make your RGB adjustments
diffuse_blue = 200;
diffuse_green = 200;
diffuse_red = 200;