Looks like rust to me.

True, but its the color of the leaf itself not growing on top of it...

You may want to take one or two out of their pots and take a look at what is going on with the bulbs... just to see if there is something suspicious below ground.

Tina

Quick update,

I've stopped watering them from on top for a week now and they seem to be improving. The only thing I an think of is that the cold weather forced it into dormancy (being that it was at 70 degrees for 7 months and then cruelly thrust outside) or that the watering on top rotted it somehow.
Thanks for the help!

Tina,
I dug up one and the bulb itself looks fine (I think). It's a healthy yellow/green and around the size of 3 golf balls. It did have a extremely thin brown crackly coating extending from the shriveled leaves, I peeled it off though. Do you think it's early dormancy?

I think they may have dropped their leaves so they could grow new leaves that are better suited to their new conditions. It's good news that the bulbs are decent size and look good! I'm no expert on hippeastrum, this is only my second year growing them. However, I have noticed that most of the plants I've recently moved outdoors have not taken the move well. Some are dropping their leaves and growing new ones. Presumably the leaves they grew while indoors were suited to the lower light levels... and now they need leaves that can handle the higher light that is available outdoors. I think your bulbs will be just fine. Cut back a bit on the watering until you see new leaves emerge. Instead of watering from above, you may want to try watering from below (by setting the pots in a container of water and allowing them to wick up moisture for about 15 minutes at each watering interval). Good luck and keep us posted!

The leaves got sun-burnt that's all. New leaves will appear, that tolerate unfiltered irradiation: So berkeleysgr8 provided the correct suggestion.

I'm very happy that one of our resident experts, haweha, agrees!