This is an idea to do with the end rod block and a cool feature I would like to see implemented into the 1.12 world of colours update. I think that it would be a cool feature to see the bottom part of the end rod(the purple part) change to match the colour of the block that it is placed on. Example: placing an end rod on red wool would change the colour of the base to red. I feel that this would add a new layer of depth to the building and lighting areas of the game. I don't know much about coding and/or modding so feel free to implement this idea into a mod if you so wish.