Not computer saavy enough to know if it could be implemented, but it seems to me that you could make the saddleblankets, etc. on the regular (reputation and store) steeds dyeable. That would be a feature I would be willing to pay for. I love my rep steeds, but their gear doesn't always match the characters that ride them the most.
Not all of us have war steeds. Some of us won't every get that far and some don't want to mess with them. Please give us the ability to dye the gear on the horses we actually do ride to match.