Custom Visual Effects for Custom Dimensions

It would be cool if we could change the texture for the sun and moon for custom dimensions without messing with the overworld textures. This would work something like this, when you make a custom dimension the game checks in textures/environment/<dimension name> for sun moon and sky box textures if it can't find a texture use the default overworld versions. This would add more visual difference to custom dimensions so they won't feel like overworld copies.