I always had problem with adjusting characters in one scene. Different creators, different textures and materials looks weird in one scene. Even original Daz figures not always fit. I tried to adjust materials or textures but have only few sufficient effect. Last time I tried to render character without textures, but still had no good results. Finally I decided to use some maps and I think that it can works.
Only maps I used are overlay around eyes to make eyesocket little bit darker, lip overlay map and iris normal map. Hairs have transmap of course and I added some backgroud. Anyway I see that human can be made with few maps instead of 500 KB of textures. Moreover character skin can be changed with diffuse and transluency color only.