So as of late I have been in full swing on my production of my Halo Machinima Sets and realized that you cannot colour decals. I think it would be a great Idea to add this as a New Forge. It would help make maps look even better and would be a great tool for Machinima set builders to personalize there sets. So Please hope 343 sees this so we can hopefully get this add in a future update.
Shoot the suggestion to Tom French on Twitter, I’m sure he’ll let you know if it’s in the pipeline or not.