I'm wondering if anyone knows either somewhere where I can get a white iris texture, or of a P6 material room node setup to change a color texture for a character's iris into a whte texture without losing much detail.

I'd still like to have the lines and such in the iris, but have the color black and white. And I've tried greyscaling a texture, but it seems to be fairly ininteresting and "flat".

it's easy to make a greyscale texture in poser 6 -- just slap an hsv node in front of the image map for the iris, and set the saturation value to 0 (connect the iris's diffuse color channel to a math -> hsv node, connect the hsv node's color channel to the texture map). that alone won't make the texture interesting, of course. i tend to do that sort of work in photoshop where i can modify the curves of the individual colour channels and get more interesting contrasts. flatness can also be combatted by making the eye textures shiny, wet, with nice specular highlights. i am on a different machine without my tutorial links, but i am sure somebody else will jump right in.

You could also just try turning down the Texture Strength - that would make the white background shine through.