Here's a little more on what I was talking about before. In the screen shot below I've got an Organic 2 shader. It's got a bunch of sub shaders that are all basically a Color Gradient with Organic 1 set on Dirt as a sub shader.

The first sub shader is the Border you mentioned in your original post. That shader controls the color between the cells (or grout if you wish).

Next I used the button that is a circle with a plus sign (not sure it's real name) to add the three other sub shaders. Enhance:C will randomly assign one of those to each cell. Notice in the preview window that some are a little green, some more red, some gray.

This helps you create a little variety in these types of shaders. Make a few sub shaders that are a little different and won't look like each tile/cell/panel are exactly the same. On the Common Tab you can also adjust how that behaves by changing the Subshader Mixing. The Blend Two option will only use the first two and will randomly blend them in each cell.

An easier way to get the hang of how all that works is playing with the Enhance:C Tile shader. Set it's Grout color to white and then start adding other sub shaders, change them to random colors and see what it does to your tiles.

PS. Sorry about the wide screen shot.

Regards,

Eric Winemiller
Digital Carvers Guild
Carrara and LightWave plug-ins