So, with things like glass, wool, terracotta, concrete, glazed terracotta, and carpets, they all only require either their white versions or whatever default version they are for printing. I've seen SO many absolutely gorgeous designs using exotic wood types that people have made in the creative server that never get printed because whoever is wanting to print said building or statue or vehicle either doesn't have access to the required wood types, either limited to very small amounts or to none at all, or lives in a region where it can't grow. I see no reason why the most commonly grown and used wood type, Spruce, be used the same way. Logs, planks, fences, stairs, everything. This would not only make it much easier for people to print things, it would also create an avenue for a much needed splash of colour in CCNet. I see no gameplay exploitation or otherwise manipulation for illegal actions that can be done using this.
Side note, I know there are some regions where even spruce doesn't grow. If it's a big enough issue, perhaps oak wood can also be used for this purpose.