Adding in ores from Mekanism. Everything seems to be fine except the tin ore texture.

Seems to be some kind of issue with the texture being grey scale. I used a resource pack to change the texture of tin ore and it works fine..

It is indeed a problem with the texture being greyscale. For some reason, java ImageIO doesn't handle that properly. (https://stackoverflow.com/questions/31312645/java-imageio-grayscale-png-issue)
I'll try to find a workaround for that behavior.