Light colors are always best to use when you are printing lithophanes. While you can use any light color you want, white is usually recommended for best results, even if you are using a low power temperature. Dark colors will not allow the light to pass through the lithophane as it should, so it is not recommended to use them. If you are new to making lithophanes, you should start out using white, and then once you get used to the process, start to experiment with light colors after that.