In latest snapshot the color palette for maps has changed.
See the picture attached for comparison: (PRE snapshot | Snapshot)
Comment from @unknown on reddit:
I think the problem here is that one brown shade changed, but not the other? Your gradients have disappeared, which is a shame. It would be helpful if you filed this as a bug.
Brown wool is the culprit on that one issue jeb mentioned, see this comparison. I have written up a suggested fix here that would also address the other problems with the map color palette update.