light the diffuse

Hi, My problems is this :- 1. I have a Vertex Buffer containing D3DFVF_XYZ & D3DFVF_TEX1 *only* (No diffuse color). 2. I have a greyscale texture. 3. I want to render the Vertex Buffer many times but changing the color of the final rendered texture. e.g change greyscale to redscale, bluescale etc etc. (At the moment i don''t mind if the color is global, but per vertex color would be nice). 4. The lights are switched off, which means I cannot change the material to change the color. 5. I could add D3DFVF_DIFFUSE to the vertex format, but I don''t want to lock the vertex buffer to change diffuse colors for every render. Do I have to use a vertex shader, and if so, what percentage of the user base would support it? Is there a way of setting the *default* diffuse color? I could then modulate texture color and diffuse color, and because there is no vertex diffuse color it will use the default. Or is there another way?? Thanks J-J-Jack the Groove