I've found when using Poser10 Comic book style render, that when a texture appears too dark, I can improve it by using low values of the intended colour or connecting the texture map in the ambient channel, this keeps the level of toon shading but forces through a bit more of the base colour. I've also found that I had to "unlearn" all the rendering rules for "realistic/raytrace" work. Since most texture shaders, especiallly character mats are optimised for raytrace it is necessary sometimes to simplify them for toons. I noticed in Boni's second image, the female to the right of the central figure is a case where I'd connect the main texture to ambient as well with 0.05 or 0.1 value, the male 3rd from left has weirdly shiney hair, my guess is that the specular node has elements that the toon renderer is misreading. I've also found that Poser's ancient "Basic Lights" set has become very useful again.